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---
title: BCD settings and BitLocker
description: This article for IT professionals describes the BCD settings that are used by BitLocker.
ms.topic: conceptual
ms.date: 11/08/2022
---
# Boot Configuration Data settings and BitLocker
This article for IT professionals describes the Boot Configuration Data (BCD) settings that are used by BitLocker.
When protecting data at rest on an operating system volume, during the boot process BitLocker verifies that the security sensitive BCD settings haven't changed since BitLocker was last enabled, resumed, or recovered.
## BitLocker and BCD Settings
In Windows 7 and Windows Server 2008 R2, BitLocker validated BCD settings with the winload, winresume, and memtest prefixes to a large degree. However, this high degree of validation caused BitLocker to go into recovery mode for benign setting changes, for example, when applying a language pack, BitLocker would enter recovery mode.
In Windows 8, Windows Server 2012, and later operating systems, BitLocker narrows the set of BCD settings validated to reduce the chance of benign changes causing a BCD validation problem. If it's believed that there's a risk in excluding a particular BCD setting from the validation profile, include that BCD setting in the BCD validation coverage to suit the preferences for validation. If a default BCD setting is found to persistently trigger a recovery for benign changes, exclude that BCD setting from the validation coverage.
### When secure boot is enabled
Computers with UEFI firmware can use secure boot to provide enhanced boot security. When BitLocker is able to use secure boot for platform and BCD integrity validation, as defined by the **Allow Secure Boot for integrity validation** group policy setting, the **Use enhanced Boot Configuration Data validation profile** group policy is ignored.
One of the benefits of using secure boot is that it can correct BCD settings during boot without triggering recovery events. Secure boot enforces the same BCD settings as BitLocker. Secure boot BCD enforcement isn't configurable from within the operating system.
## Customizing BCD validation settings
To modify the BCD settings that are validated by BitLocker, the administrator will add or exclude BCD settings from the platform validation profile by enabling and configuring the **Use enhanced Boot Configuration Data validation profile** group policy setting.
For the purposes of BitLocker validation, BCD settings are associated with a specific set of Microsoft boot applications. These BCD settings can also be applied to the other Microsoft boot applications that aren't part of the set to which the BCD settings are already applicable for. This setting can be done by attaching any of the following prefixes to the BCD settings that are being entered in the group policy settings dialog:
- winload
- winresume
- memtest
- all of the above
All BCD settings are specified by combining the prefix value with either a hexadecimal (hex) value or a "friendly name."
The BCD setting hex value is reported when BitLocker enters recovery mode and is stored in the event log (event ID 523). The hex value uniquely identifies the BCD setting that caused the recovery event.
You can quickly obtain the friendly name for the BCD settings on a computer by using the command `bcdedit.exe /enum all`.
Not all BCD settings have friendly names; for those settings without a friendly name, the hex value is the only way to configure an exclusion policy.
When specifying BCD values in the **Use enhanced Boot Configuration Data validation profile** group policy setting, use the following syntax:
- Prefix the setting with the boot application prefix
- Append a colon `:`
- Append either the hex value or the friendly name
- If entering more than one BCD setting, each BCD setting will need to be entered on a new line
For example, either "`winload:hypervisordebugport`" or "`winload:0x250000f4`" yields the same value.
A setting that applies to all boot applications may be applied only to an individual application. However, the reverse isn't true. For example, one can specify either "`all:locale`" or "`winresume:locale`", but as the BCD setting "`win-pe`" doesn't apply to all boot applications, "`winload:winpe`" is valid, but "`all:winpe`" isn't valid. The setting that controls boot debugging ("`bootdebug`" or 0x16000010) will always be validated and will have no effect if it's included in the provided fields.
> [!NOTE]
> Take care when configuring BCD entries in the Group Policy setting. The Local Group Policy Editor does not validate the correctness of the BCD entry. BitLocker will fail to be enabled if the Group Policy setting specified is invalid.
### Default BCD validation profile
The following table contains the default BCD validation profile used by BitLocker in Windows 8, Windows Server 2012, and subsequent versions:
| Hex Value | Prefix | Friendly Name |
| - | - | - |
| 0x11000001 | all | device|
| 0x12000002 | all | path|
| 0x12000030 | all | loadoptions|
| 0x16000010 | all | bootdebug|
| 0x16000040 | all | advancedoptions|
| 0x16000041 | all| optionsedit|
| 0x16000048| all| nointegritychecks|
| 0x16000049| all| testsigning|
| 0x16000060| all| isolatedcontext|
| 0x1600007b| all| forcefipscrypto|
| 0x22000002| winload| systemroot|
| 0x22000011| winload| kernel|
| 0x22000012| winload| hal|
| 0x22000053| winload| evstore|
| 0x25000020| winload| nx|
| 0x25000052| winload| restrictapiccluster|
| 0x26000022| winload| winpe|
| 0x26000025 |winload|lastknowngood|
| 0x26000081| winload| safebootalternateshell|
| 0x260000a0| winload| debug|
| 0x260000f2| winload| hypervisordebug|
| 0x26000116| winload| hypervisorusevapic|
| 0x21000001| winresume| filedevice|
| 0x22000002| winresume| filepath|
| 0x26000006| winresume| debugoptionenabled|
### Full list of friendly names for ignored BCD settings
The following list is a full list of BCD settings with friendly names, which are ignored by default. These settings aren't part of the default BitLocker validation profile, but can be added if you see a need to validate any of these settings before allowing a BitLocker-protected operating system drive to be unlocked.
> [!NOTE]
> Additional BCD settings exist that have hex values but do not have friendly names. These settings are not included in this list.
| Hex Value | Prefix | Friendly Name |
| - | - | - |
| 0x12000004 | all | description |
| 0x12000005 | all | locale |
| 0x12000016 | all | targetname |
| 0x12000019| all| busparams|
| 0x1200001d| all| key|
| 0x1200004a| all| fontpath|
| 0x14000006| all| inherit|
| 0x14000008| all| recoverysequence|
| 0x15000007| all| truncatememory|
| 0x1500000c| all| firstmegabytepolicy|
| 0x1500000d| all| relocatephysical|
| 0x1500000e| all| avoidlowmemory|
| 0x15000011| all| debugtype|
| 0x15000012 |all|debugaddress|
| 0x15000013| all| debugport|
| 0x15000014|all|baudrate|
| 0x15000015 | all| channel|
| 0x15000018 | all| debugstart|
| 0x1500001a | all| hostip|
| 0x1500001b | all| port|
| 0x15000022 | all| emsport|
| 0x15000023 | all| emsbaudrate|
| 0x15000042 | all| keyringaddress|
| 0x15000047 | all| configaccesspolicy|
| 0x1500004b | all| integrityservices|
| 0x1500004c | all| volumebandid|
| 0x15000051 | all| initialconsoleinput|
| 0x15000052 | all| graphicsresolution|
| 0x15000065 | all| displaymessage|
| 0x15000066 | all| displaymessageoverride|
| 0x15000081 | all| logcontrol|
| 0x16000009 | all| recoveryenabled|
| 0x1600000b | all| badmemoryaccess|
| 0x1600000f | all| traditionalkseg|
| 0x16000017 | all| noumex|
| 0x1600001c | all| dhcp|
| 0x1600001e | all| vm|
| 0x16000020 | all| bootems|
| 0x16000046 | all| graphicsmodedisabled|
| 0x16000050 | all| extendedinput|
| 0x16000053 | all| restartonfailure|
| 0x16000054 | all| highestmode|
| 0x1600006c | all| bootuxdisabled|
| 0x16000072 | all| nokeyboard|
| 0x16000074 | all| bootshutdowndisabled|
| 0x1700000a | all| badmemorylist|
| 0x17000077 | all| allowedinmemorysettings|
| 0x22000040 | all| fverecoveryurl|
| 0x22000041 | all| fverecoverymessage|
| 0x31000003 | all| ramdisksdidevice|
| 0x32000004 | all| ramdisksdipath|
| 0x35000001| all | ramdiskimageoffset|
| 0x35000002 | all| ramdisktftpclientport|
| 0x35000005 | all| ramdiskimagelength|
| 0x35000007 | all| ramdisktftpblocksize|
| 0x35000008 | all| ramdisktftpwindowsize|
| 0x36000006 | all| exportascd|
| 0x36000009 | all| ramdiskmcenabled|
| 0x3600000a | all| ramdiskmctftpfallback|
| 0x3600000b | all| ramdisktftpvarwindow|
| 0x21000001 | winload| osdevice|
| 0x22000013 | winload| dbgtransport|
| 0x220000f9 | winload| hypervisorbusparams|
| 0x22000110 | winload| hypervisorusekey|
| 0x23000003 |winload| resumeobject|
| 0x25000021| winload| pae|
| 0x25000031 |winload| removememory|
| 0x25000032 | winload| increaseuserva|
| 0x25000033 | winload| perfmem|
| 0x25000050 | winload| clustermodeaddressing|
| 0x25000055 | winload| x2apicpolicy|
| 0x25000061 | winload| numproc|
| 0x25000063 | winload| configflags|
| 0x25000066| winload| groupsize|
| 0x25000071 | winload| msi|
| 0x25000072 | winload| pciexpress|
| 0x25000080 | winload| safeboot|
| 0x250000a6 | winload| tscsyncpolicy|
| 0x250000c1| winload| driverloadfailurepolicy|
| 0x250000c2| winload| bootmenupolicy|
| 0x250000e0 |winload| bootstatuspolicy|
| 0x250000f0 | winload| hypervisorlaunchtype|
| 0x250000f3 | winload| hypervisordebugtype|
| 0x250000f4 | winload| hypervisordebugport|
| 0x250000f5 | winload| hypervisorbaudrate|
| 0x250000f6 | winload| hypervisorchannel|
| 0x250000f7 | winload| bootux|
| 0x250000fa | winload| hypervisornumproc|
| 0x250000fb | winload| hypervisorrootprocpernode|
| 0x250000fd | winload| hypervisorhostip|
| 0x250000fe | winload| hypervisorhostport|
| 0x25000100 | winload| tpmbootentropy|
| 0x25000113 | winload| hypervisorrootproc|
| 0x25000115 | winload| hypervisoriommupolicy|
| 0x25000120 | winload| xsavepolicy|
| 0x25000121 | winload| xsaveaddfeature0|
| 0x25000122 | winload| xsaveaddfeature1|
| 0x25000123 | winload| xsaveaddfeature2|
| 0x25000124 | winload| xsaveaddfeature3|
| 0x25000125 | winload| xsaveaddfeature4|
| 0x25000126 | winload| xsaveaddfeature5|
| 0x25000127 | winload| xsaveaddfeature6|
| 0x25000128 | winload| xsaveaddfeature7|
| 0x25000129 | winload| xsaveremovefeature|
| 0x2500012a | winload| xsaveprocessorsmask|
| 0x2500012b | winload| xsavedisable|
| 0x25000130 | winload| claimedtpmcounter|
| 0x26000004 | winload| stampdisks|
| 0x26000010 | winload| detecthal|
| 0x26000024 | winload| nocrashautoreboot|
| 0x26000030 | winload| nolowmem|
| 0x26000040 | winload| vga|
| 0x26000041 | winload| quietboot|
| 0x26000042 | winload| novesa|
| 0x26000043 | winload| novga|
| 0x26000051 | winload| usephysicaldestination|
| 0x26000054 | winload| uselegacyapicmode|
| 0x26000060 | winload| onecpu|
| 0x26000062 | winload| maxproc|
| 0x26000064 | winload| maxgroup|
| 0x26000065 | winload| groupaware|
| 0x26000070| winload| usefirmwarepcisettings|
| 0x26000090 | winload| bootlog|
| 0x26000091 | winload| sos|
| 0x260000a1 | winload| halbreakpoint|
| 0x260000a2 | winload| useplatformclock|
| 0x260000a3 |winload| forcelegacyplatform|
| 0x260000a4 | winload| useplatformtick|
| 0x260000a5 | winload| disabledynamictick|
| 0x260000b0 | winload| ems|
| 0x260000c3 | winload| onetimeadvancedoptions|
| 0x260000c4 | winload| onetimeoptionsedit|
| 0x260000e1| winload| disableelamdrivers|
| 0x260000f8 | winload| hypervisordisableslat|
| 0x260000fc | winload| hypervisoruselargevtlb|
| 0x26000114 | winload| hypervisordhcp|
| 0x21000005 | winresume| associatedosdevice|
| 0x25000007 | winresume| bootux|
| 0x25000008 | winresume| bootmenupolicy|
| 0x26000003| winresume |customsettings|
| 0x26000004 | winresume| pae|
| 0x25000001 | memtest| passcount|
| 0x25000002 | memtest| testmix|
| 0x25000005 | memtest| stridefailcount|
| 0x25000006 | memtest| invcfailcount|
| 0x25000007 | memtest| matsfailcount|
| 0x25000008 | memtest| randfailcount|
| 0x25000009 |memtest| chckrfailcount|
| 0x26000003| memtest| cacheenable|
| 0x26000004 | memtest| failuresenabled|

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### YamlMime:FAQ
metadata:
title: BitLocker and Active Directory Domain Services (AD DS) FAQ (Windows 10)
description: Learn more about how BitLocker and Active Directory Domain Services (AD DS) can work together to keep devices secure.
ms.collection:
- highpri
- tier1
ms.topic: faq
ms.date: 11/08/2022
author: paolomatarazzo
ms.author: paoloma
appliesto:
- ✅ <a href=https://learn.microsoft.com/windows/release-health/supported-versions-windows-client target=_blank>Windows 11</a>
- ✅ <a href=https://learn.microsoft.com/windows/release-health/supported-versions-windows-client target=_blank>Windows 10</a>
- ✅ <a href=https://learn.microsoft.com/windows/release-health/windows-server-release-info target=_blank>Windows Server 2022</a>
- ✅ <a href=https://learn.microsoft.com/windows/release-health/windows-server-release-info target=_blank>Windows Server 2019</a>
- ✅ <a href=https://learn.microsoft.com/windows/release-health/windows-server-release-info target=_blank>Windows Server 2016</a>
title: BitLocker and Active Directory Domain Services (AD DS) FAQ
summary: |
**Applies to:**
- Windows 10 and later
- Windows Server 2016 and later
sections:
- name: Ignored
questions:
- question: |
What type of information is stored in AD DS?
answer: |
Stored information | Description
-------------------|------------
Hash of the TPM owner password | Beginning with Windows 10, the password hash isn't stored in AD DS by default. The password hash can be stored only if the TPM is owned and the ownership was taken by using components of Windows 8.1 or earlier, such as the BitLocker Setup Wizard or the TPM snap-in.
BitLocker recovery password | The recovery password allows unlocking of and access to the drive after a recovery incident. Domain administrators can view the BitLocker recovery password by using the BitLocker Recovery Password Viewer. For more information about this tool, see [BitLocker: Use BitLocker Recovery Password Viewer](bitlocker-use-bitlocker-recovery-password-viewer.md).
BitLocker key package | The key package helps to repair damage to the hard disk that would otherwise prevent standard recovery. Using the key package for recovery requires the BitLocker Repair Tool, `Repair-bde`.
- question: |
What if BitLocker is enabled on a computer before the computer has joined the domain?
answer: |
If BitLocker is enabled on a drive before Group Policy has been applied to enforce a backup, the recovery information won't be automatically backed up to AD DS when the computer joins the domain or when Group Policy is subsequently applied. However, the Group Policy settings **Choose how BitLocker-protected operating system drives can be recovered**, **Choose how BitLocker-protected fixed drives can be recovered**, and **Choose how BitLocker-protected removable drives can be recovered** can be chosen to require the computer to be connected to a domain before BitLocker can be enabled to help ensure that recovery information for BitLocker-protected drives in the organization is backed up to AD DS.
For more info, see [BitLocker Group Policy settings](bitlocker-group-policy-settings.md).
The BitLocker Windows Management Instrumentation (WMI) interface does allow administrators to write a script to back up or synchronize an online client's existing recovery information. However, BitLocker doesn't automatically manage this process. The `manage-bde.exe` command-line tool can also be used to manually back up recovery information to AD DS. For example, to back up all of the recovery information for the `$env:SystemDrive` to AD DS, the following command script can be used from an elevated command prompt:
```powershell
$BitLocker = Get-BitLockerVolume -MountPoint $env:SystemDrive
$RecoveryProtector = $BitLocker.KeyProtector | Where-Object { $_.KeyProtectorType -eq 'RecoveryPassword' }
Backup-BitLockerKeyProtector -MountPoint $env:SystemDrive -KeyProtectorId $RecoveryProtector.KeyProtectorID
BackupToAAD-BitLockerKeyProtector -MountPoint $env:SystemDrive -KeyProtectorId $RecoveryProtector.KeyProtectorID
```
> [!IMPORTANT]
> Joining a computer to the domain should be the first step for new computers within an organization. After computers are joined to a domain, storing the BitLocker recovery key to AD DS is automatic (when enabled in Group Policy).
- question: |
Is there an event log entry recorded on the client computer to indicate the success or failure of the Active Directory backup?
answer: |
Yes, an event log entry that indicates the success or failure of an Active Directory backup is recorded on the client computer. However, even if an event log entry says "Success," the information could have been subsequently removed from AD DS, or BitLocker could have been reconfigured in such a way that the Active Directory information can no longer unlock the drive (such as by removing the recovery password key protector). In addition, it's also possible that the log entry could be spoofed.
Ultimately, determining whether a legitimate backup exists in AD DS requires querying AD DS with domain administrator credentials by using the BitLocker password viewer tool.
- question: |
If I change the BitLocker recovery password on my computer and store the new password in AD DS, will AD DS overwrite the old password?
answer: |
No. By design, BitLocker recovery password entries don't get deleted from AD DS. Therefore, multiple passwords might be seen for each drive. To identify the latest password, check the date on the object.
- question: |
What happens if the backup initially fails? Will BitLocker retry it?
answer: |
If the backup initially fails, such as when a domain controller is unreachable at the time when the BitLocker setup wizard is run, BitLocker doesn't try again to back up the recovery information to AD DS.
When an administrator selects the **Require BitLocker backup to AD DS** check box of the **Store BitLocker recovery information in Active Directory Domain Service (Windows 2008 and Windows Vista)** policy setting, or the equivalent **Do not enable BitLocker until recovery information is stored in AD DS for (operating system | fixed data | removable data) drives** check box in any of the **Choose how BitLocker-protected operating system drives can be recovered**, **Choose how BitLocker-protected fixed data drives can be recovered**, and **Choose how BitLocker-protected removable data drives can be recovered** policy settings, users can't enable BitLocker unless the computer is connected to the domain and the backup of BitLocker recovery information to AD DS succeeds. With these settings configured if the backup fails, BitLocker can't be enabled, ensuring that administrators will be able to recover BitLocker-protected drives in the organization.
For more info, see [BitLocker Group Policy settings](bitlocker-group-policy-settings.md).
When an administrator clears these check boxes, the administrator is allowing a drive to be BitLocker-protected without having the recovery information successfully backed up to AD DS; however, BitLocker won't automatically retry the backup if it fails. Instead, administrators can create a backup script, as described earlier in [What if BitLocker is enabled on a computer before the computer has joined the domain?](#what-if-bitlocker-is-enabled-on-a-computer-before-the-computer-has-joined-the-domain-) to capture the information after connectivity is restored.

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---
title: BitLocker basic deployment
description: This article for the IT professional explains how BitLocker features can be used to protect your data through drive encryption.
ms.topic: conceptual
ms.date: 11/08/2022
---
# BitLocker basic deployment
This article for the IT professional explains how BitLocker features can be used to protect data through drive encryption.
## Using BitLocker to encrypt volumes
BitLocker provides full volume encryption (FVE) for operating system volumes, and fixed and removable data drives. To support fully encrypted operating system drives, BitLocker uses an unencrypted system partition for the files required to boot, decrypt, and load the operating system. This volume is automatically created during a new installation of both client and server operating systems.
If the drive was prepared as a single contiguous space, BitLocker requires a new volume to hold the boot files. BdeHdCfg.exe can create these volumes.
> [!NOTE]
> For more info about using this tool, see [Bdehdcfg](/windows-server/administration/windows-commands/bdehdcfg) in the Command-Line Reference.
BitLocker encryption can be enabled and managed using the following methods:
- BitLocker control panel
- Windows Explorer
- `manage-bde.exe` command-line interface
- BitLocker Windows PowerShell cmdlets
### Encrypting volumes using the BitLocker control panel
Encrypting volumes with the BitLocker control panel (select **Start**, enter `Bitlocker`, select **Manage BitLocker**) is how many users will use BitLocker. The name of the BitLocker control panel is BitLocker Drive Encryption. The BitLocker control panel supports encrypting operating system, fixed data, and removable data volumes. The BitLocker control panel will organize available drives in the appropriate category based on how the device reports itself to Windows. Only formatted volumes with assigned drive letters will appear properly in the BitLocker control panel applet.
To start encryption for a volume, select **Turn on BitLocker** for the appropriate drive to initialize the **BitLocker Drive Encryption Wizard**. **BitLocker Drive Encryption Wizard** options vary based on volume type (operating system volume or data volume).
#### Operating system volume
For the operating system volume the **BitLocker Drive Encryption Wizard** presents several screens that prompt for options while it performs several actions:
1. When the **BitLocker Drive Encryption Wizard** first launches, it verifies the computer meets the BitLocker system requirements for encrypting an operating system volume. By default, the system requirements are:
|Requirement|Description|
|--- |--- |
|Hardware configuration|The computer must meet the minimum requirements for the supported Windows versions.|
|Operating system|BitLocker is an optional feature that can be installed by Server Manager on Windows Server 2012 and later.|
|Hardware TPM|TPM version 1.2 or 2.0. <br><br> A TPM isn't required for BitLocker; however, only a computer with a TPM can provide the additional security of pre-startup system integrity verification and multifactor authentication.|
|UEFI firmware/BIOS configuration|<ul><li> A Trusted Computing Group (TCG)-compliant BIOS or UEFI firmware.</li> <li> The boot order must be set to start first from the hard disk, and not the USB or CD drives.</li> <li> The firmware must be able to read from a USB flash drive during startup.</li></ul>|
|File system| One FAT32 partition for the system drive and one NTFS partition for the operating system drive. This requirement is applicable for computers that boot natively with UEFI firmware. <br/> For computers with legacy BIOS firmware, at least two NTFS disk partitions, one for the system drive and one for the operating system drive. <br/> For either firmware, the system drive partition must be at least 350 megabytes (MB) and set as the active partition.|
|Hardware encrypted drive prerequisites (optional)|To use a hardware encrypted drive as the boot drive, the drive must be in the uninitialized state and in the security inactive state. In addition, the system must always boot with native UEFI version 2.3.1 or higher and the CSM (if any) disabled.|
If the volume doesn't pass the initial configuration for BitLocker, the user is presented with an error dialog describing the appropriate actions to be taken.
2. Upon passing the initial configuration, users may be prompted to enter a password for the volume, for example, if a TPM isn't available. If a TPM is available, the password screen will be skipped.
3. After the initial configuration/password screens, a recovery key will be generated. The **BitLocker Drive Encryption Wizard** will prompt for a location to save the recovery key. A BitLocker recovery key is a special key that is created when BitLocker Drive Encryption is turned on for the first time on each drive that is encrypted. The recovery key can be used to gain access to the computer if:
- The drive that Windows is installed on (the operating system drive) is encrypted using BitLocker Drive Encryption
- BitLocker detects a condition that prevents it from unlocking the drive when the computer is starting up
A recovery key can also be used to gain access to the files and folders on a removable data drive (such as an external hard drive or USB flash drive) that is encrypted using BitLocker To Go, if for some reason the password is forgotten or the computer can't access the drive.
The recovery key can be stored using the following methods:
- **Save to your Azure AD account** (if applicable)
- **Save to a USB flash drive**
- **Save to a file** - the file needs to be saved to a location that isn't on the computer itself such as a network folder or OneDrive
- **Print the recovery key**
The recovery key can't be stored at the following locations:
- The drive being encrypted
- The root directory of a non-removable/fixed drive
- An encrypted volume
> [!TIP]
> Ideally, a computer's recovery key should be stored separate from the computer itself.
> [!NOTE]
> After a recovery key is created, the BitLocker control panel can be used to make additional copies of the recovery key.
4. The **BitLocker Drive Encryption Wizard** will then prompt how much of the drive to encrypt. The **BitLocker Drive Encryption Wizard** will have two options that determine how much of the drive is encrypted:
- **Encrypt used disk space only** - Encrypts only disk space that contains data.
- **Encrypt entire drive** - Encrypts the entire volume including free space. Also known as full disk encryption.
Each of the methods is recommended in the following scenarios:
- **Encrypt used disk space only**:
- The drive has never had data
- Formatted or erased drives that in the past have never had confidential data that was never encrypted
- **Encrypt entire drive** (full disk encryption):
- Drives that currently have data
- Drives that currently have an operating system
- Formatted or erased drives that in the past had confidential data that was never encrypted
> [!IMPORTANT]
> Deleted files appear as free space to the file system, which isn't encrypted by **used disk space only**. Until they are wiped or overwritten, deleted files hold information that could be recovered with common data forensic tools.
5. The **BitLocker Drive Encryption Wizard** will then prompt for an encryption mode:
- **New encryption mode**
- **Compatible mode**
Normally **New encryption mode** should be chosen, but if the drive will be potentially moved to another computer with an older Windows operating system, then select **Compatible mode**.
6. After selecting an encryption mode, the **BitLocker Drive Encryption Wizard** will give the option of running a BitLocker system check via the option **Run BitLocker system check**. This system check will ensure that BitLocker can properly access the recovery and encryption keys before the volume encryption begins. it's recommended run this system check before starting the encryption process. If the system check isn't run and a problem is encountered when the operating system attempts to start, the user will need to provide the recovery key to start Windows.
After completing the system check (if selected), the **BitLocker Drive Encryption Wizard** will begin encryption. A reboot may be initiated to start encryption. If a reboot was initiated, if there was no TPM and a password was specified, the password will need to be entered to boot into the operating system volume.
Users can check encryption status by checking the system notification area or the BitLocker control panel.
Until encryption is completed, the only available options for managing BitLocker involve manipulation of the password protecting the operating system volume, backing up the recovery key, and turning off BitLocker.
#### Data volume
Encrypting data volumes using the BitLocker control panel works in a similar fashion to encryption of the operating system volumes. Users select **Turn on BitLocker** within the BitLocker control panel to begin the **BitLocker Drive Encryption Wizard**.
1. Upon launching the **BitLocker Drive Encryption Wizard**, unlike for operating system volumes, data volumes aren't required to pass any configuration tests for the **BitLocker Drive Encryption Wizard** to proceed
2. A choice of authentication methods to unlock the drive appears. The available options are:
- **Use a password to unlock the drive**
- **Use my smart card to unlock the drive**
- **Automatically unlock this drive on this computer** - Disabled by default but if enabled, this option will unlock the data volume without user input when the operating system volume is unlocked.
3. The **BitLocker Drive Encryption Wizard** presents options for storage of the recovery key. These options are the same as for operating system volumes:
- **Save to your Azure AD account** (if applicable)
- **Save to a USB flash drive**
- **Save to a file** - the file needs to be saved to a location that isn't on the computer itself such as a network folder or OneDrive
- **Print the recovery key**
4. After saving the recovery key, the **BitLocker Drive Encryption Wizard** will show available options for encryption. These options are the same as for operating system volumes:
- **Encrypt used disk space only** - Encrypts only disk space that contains data.
- **Encrypt entire drive** - Encrypts the entire volume including free space. Also known as full disk encryption.
5. The **BitLocker Drive Encryption Wizard** will then prompt for an encryption mode:
- **New encryption mode**
- **Compatible mode**
Normally **New encryption mode** should be chosen, but if the drive will be potentially moved to another computer with an older Windows operating system, then select **Compatible mode**.
6. The **BitLocker Drive Encryption Wizard** will display a final confirmation screen before the encryption process begins. Selecting **Start encrypting** begins encryption.
Encryption status displays in the notification area or within the BitLocker control panel.
### OneDrive option
There's an option for storing the BitLocker recovery key using OneDrive. This option requires that computers aren't members of a domain and that the user is using a Microsoft Account. Local accounts don't give the option to use OneDrive. Using the OneDrive option is the default recommended recovery key storage method for computers that aren't joined to a domain.
Users can verify whether the recovery key was saved properly by checking OneDrive for the BitLocker folder. The BitLocker folder on OneDrive is created automatically during the save process. The folder will contain two files, a `readme.txt` and the recovery key. For users storing more than one recovery password on their OneDrive, they can identify the required recovery key by looking at the file name. The recovery key ID is appended to the end of the file name.
### Using BitLocker within Windows Explorer
Windows Explorer allows users to launch the **BitLocker Drive Encryption Wizard** by right-clicking a volume and selecting **Turn On BitLocker**. This option is available on client computers by default. On servers, the BitLocker feature and the Desktop-Experience feature must first be installed for this option to be available. After selecting **Turn on BitLocker**, the wizard works exactly as it does when launched using the BitLocker control panel.
## Down-level compatibility
The following table shows the compatibility matrix for systems that have been BitLocker enabled and then presented to a different version of Windows.
Table 1: Cross compatibility for Windows 11, Windows 10, Windows 8.1, Windows 8, and Windows 7 encrypted volumes
|Encryption Type|Windows 11, Windows 10, and Windows 8.1|Windows 8|Windows 7|
|---|---|---|---|
|Fully encrypted on Windows 8|Presents as fully encrypted|N/A|Presented as fully encrypted|
|Used Disk Space Only encrypted on Windows 8|Presents as encrypt on write|N/A|Presented as fully encrypted|
|Fully encrypted volume from Windows 7|Presents as fully encrypted|Presented as fully encrypted|N/A|
|Partially encrypted volume from Windows 7|Windows 11, Windows 10, and Windows 8.1 will complete encryption regardless of policy|Windows 8 will complete encryption regardless of policy|N/A|
## Encrypting volumes using the `manage-bde.exe` command-line interface
`Manage-bde.exe` is a command-line utility that can be used for scripting BitLocker operations. `Manage-bde.exe` offers additional options not displayed in the BitLocker control panel. For a complete list of the options, see [Manage-bde](/windows-server/administration/windows-commands/manage-bde).
`Manage-bde.exe` offers a multitude of wider options for configuring BitLocker. Using the command syntax may require care. For example, using just the `manage-bde.exe -on` command on a data volume will fully encrypt the volume without any authenticating protectors. A volume encrypted in this manner still requires user interaction to turn on BitLocker protection, even though the command successfully completed. For the volume to be fully protected, an authentication method needs to also be added to the volume in addition to running the `manage-bde.exe`command.
Command-line users need to determine the appropriate syntax for a given situation. The following section covers general encryption for operating system volumes and data volumes.
### Operating system volume commands
Listed below are examples of basic valid commands for operating system volumes. In general, using only the `manage-bde.exe -on <drive letter>` command encrypts the operating system volume with a TPM-only protector and no recovery key. However, many environments require more secure protectors such as passwords or PIN and expect to be able to recover information with a recovery key.
#### Determining volume status
A good practice when using `manage-bde.exe` is to determine the volume status on the target system. Use the following command to determine volume status:
`manage-bde.exe -status`
This command returns the volumes on the target, current encryption status, and volume type (operating system or data) for each volume. Using this information, users can determine the best encryption method for their environment.
#### Enabling BitLocker without a TPM
Suppose BitLocker is desired on a computer without a TPM. In this scenario, a USB flash drive is needed as a startup key for the operating system volume. The startup key will then allow the computer to boot. To create the startup key using `manage-bde.exe`, the `-protectors` switch would be used specifying the `-startupkey` option. Assuming the USB flash drive is drive letter `E:`, then the following `manage-bde.exe` commands would be used t create the startup key and start the BitLocker encryption:
```powershell
manage-bde.exe -protectors -add C: -startupkey E:
manage-bde.exe -on C:
```
If prompted, reboot the computer to complete the encryption process.
#### Enabling BitLocker with a TPM only
It's possible to encrypt the operating system volume without any defined protectors by using `manage-bde.exe`. Use this command:
```cmd
manage-bde.exe -on C:
```
This command will encrypt the drive using the TPM as the protector. If users are unsure of the protector for a volume, they can use the `-protectors` option in `manage-bde.exe` to list this information by executing the following command:
```cmd
manage-bde.exe -protectors -get <volume>
```
#### Provisioning BitLocker with two protectors
Another example is a user on a non-TPM hardware who wishes to add a password and SID-based protector to the operating system volume. In this instance, the user adds the protectors first. Adding the protectors is done with the command:
```cmd
manage-bde.exe -protectors -add C: -pw -sid <user or group>
```
This command requires the user to enter and then confirm the password protectors before adding them to the volume. With the protectors enabled on the volume, the user just needs to turn on BitLocker.
### Data volume commands
Data volumes use the same syntax for encryption as operating system volumes but they don't require protectors for the operation to complete. Encrypting data volumes can be done using the base command:
```cmd
manage-bde.exe -on <drive letter>
```
Or users can choose to add protectors to the volume. It is recommended to add at least one primary protector and a recovery protector to a data volume.
#### Enabling BitLocker with a password
A common protector for a data volume is the password protector. In the example below, a password protector is added to the volume and turn on BitLocker.
```powershell
manage-bde.exe -protectors -add -pw C:
manage-bde.exe -on C:
```
## Encrypting volumes using the BitLocker Windows PowerShell cmdlets
Windows PowerShell cmdlets provide an alternative way to work with BitLocker. Using Windows PowerShell's scripting capabilities, administrators can integrate BitLocker options into existing scripts with ease. The list below displays the available BitLocker cmdlets.
|Name|Parameters|
|--- |--- |
|**Add-BitLockerKeyProtector**|<li>ADAccountOrGroup<li>ADAccountOrGroupProtector<li>Confirm<li>MountPoint<li>Password<li>PasswordProtector<li>Pin<li>RecoveryKeyPath<li>RecoveryKeyProtector<li>RecoveryPassword<li>RecoveryPasswordProtector<li>Service<li>StartupKeyPath<li>StartupKeyProtector<li>TpmAndPinAndStartupKeyProtector<li>TpmAndPinProtector<li>TpmAndStartupKeyProtector<li>TpmProtector<li>WhatIf|
|**Backup-BitLockerKeyProtector**|<li>Confirm<li>KeyProtectorId<li>MountPoint<li>WhatIf|
|**Disable-BitLocker**|<li>Confirm<li>MountPoint<li>WhatIf|
|**Disable-BitLockerAutoUnlock**|<li>Confirm<li>MountPoint<li>WhatIf|
|**Enable-BitLocker**|<li>AdAccountOrGroup<li>AdAccountOrGroupProtector<li>Confirm<li>EncryptionMethod<li>HardwareEncryption<li>Password<li>PasswordProtector<li>Pin<li>RecoveryKeyPath<li>RecoveryKeyProtector<li>RecoveryPassword<li>RecoveryPasswordProtector<li>Service<li>SkipHardwareTest<li>StartupKeyPath<li>StartupKeyProtector<li>TpmAndPinAndStartupKeyProtector<li>TpmAndPinProtector<li>TpmAndStartupKeyProtector<li>TpmProtector<li>UsedSpaceOnly<li>WhatIf|
|**Enable-BitLockerAutoUnlock**|<li>Confirm<li>MountPoint<li>WhatIf|
|**Get-BitLockerVolume**|<li>MountPoint|
|**Lock-BitLocker**|<li>Confirm<li>ForceDismount<li>MountPoint<li>WhatIf|
|**Remove-BitLockerKeyProtector**|<li>Confirm<li>KeyProtectorId<li>MountPoint<li>WhatIf|
|**Resume-BitLocker**|<li>Confirm<li>MountPoint<li>WhatIf|
|**Suspend-BitLocker**|<li>Confirm<li>MountPoint<li>RebootCount<li>WhatIf|
|**Unlock-BitLocker**|<li>AdAccountOrGroup<li>Confirm<li>MountPoint<li>Password<li>RecoveryKeyPath<li>RecoveryPassword<li>RecoveryPassword<li>WhatIf|
Similar to `manage-bde.exe`, the Windows PowerShell cmdlets allow configuration beyond the options offered in the control panel. As with `manage-bde.exe`, users need to consider the specific needs of the volume they're encrypting prior to running Windows PowerShell cmdlets.
A good initial step is to determine the current state of the volume(s) on the computer. You can do this using the `Get-BitLocker` volume PowerShell cmdlet. The output from this cmdlet displays information on the volume type, protectors, protection status, and other useful information.
Occasionally, all protectors may not be shown when using **Get-BitLockerVolume** due to lack of space in the output display. If all of the protectors for a volume aren't seen, the Windows PowerShell pipe command (`|`) can be used to format a listing of the protectors.
> [!NOTE]
> In the event that there are more than four protectors for a volume, the pipe command may run out of display space. For volumes with more than four protectors, use the method described in the section below to generate a listing of all protectors with protector ID.
```powershell
Get-BitLockerVolume C: | fl
```
If the existing protectors need to be removed prior to provisioning BitLocker on the volume, the `Remove-BitLockerKeyProtector` cmdlet can be used. Accomplishing this action requires the GUID associated with the protector to be removed.
A simple script can pipe out the values of each **Get-BitLockerVolume** return to another variable as seen below:
```powershell
$vol = Get-BitLockerVolume
$keyprotectors = $vol.KeyProtector
```
Using this script, the information in the **$keyprotectors** variable can be displayed to determine the GUID for each protector. This information can then be used to remove the key protector for a specific volume using the command:
```powershell
Remove-BitLockerKeyProtector <volume>: -KeyProtectorID "{GUID}"
```
> [!NOTE]
> The BitLocker cmdlet requires the key protector GUID (enclosed in quotation marks) to execute. Ensure the entire GUID, with braces, is included in the command.
### Operating system volume PowerShell cmdlets
Using the BitLocker Windows PowerShell cmdlets is similar to working with the `manage-bde.exe` tool for encrypting operating system volumes. Windows PowerShell offers users flexibility. For example, users can add the desired protector as part command for encrypting the volume. Below are examples of common user scenarios and steps to accomplish them using the BitLocker cmdlets for Windows PowerShell.
To enable BitLocker with just the TPM protector, use this command:
```powershell
Enable-BitLocker C:
```
The example below adds one additional protector, the StartupKey protectors, and chooses to skip the BitLocker hardware test. In this example, encryption starts immediately without the need for a reboot.
```powershell
Enable-BitLocker C: -StartupKeyProtector -StartupKeyPath <path> -SkipHardwareTest
```
### Data volume PowerShell cmdlets
Data volume encryption using Windows PowerShell is the same as for operating system volumes. You should add the desired protectors prior to encrypting the volume. The following example adds a password protector to the E: volume using the variable $pw as the password. The $pw variable is held as a SecureString value to store the user-defined password. Last, encryption begins.
```powershell
$pw = Read-Host -AsSecureString
<user inputs password>
Enable-BitLockerKeyProtector E: -PasswordProtector -Password $pw
```
### Using an SID-based protector in Windows PowerShell
The **ADAccountOrGroup** protector is an Active Directory SID-based protector. This protector can be added to both operating system and data volumes, although it doesn't unlock operating system volumes in the pre-boot environment. The protector requires the SID for the domain account or group to link with the protector. BitLocker can protect a cluster-aware disk by adding an SID-based protector for the Cluster Name Object (CNO) that lets the disk properly failover and unlock to any member computer of the cluster.
> [!WARNING]
> The SID-based protector requires the use of an additional protector such as TPM, PIN, recovery key, etc. when used on operating system volumes.
To add an **ADAccountOrGroup** protector to a volume, either the domain SID is needed or the group name preceded by the domain and a backslash. In the example below, the **CONTOSO\\Administrator** account is added as a protector to the data volume G.
```powershell
Enable-BitLocker G: -AdAccountOrGroupProtector -AdAccountOrGroup CONTOSO\Administrator
```
For users who wish to use the SID for the account or group, the first step is to determine the SID associated with the account. To get the specific SID for a user account in Windows PowerShell, use the following command:
```powershell
Get-ADUser -filter {samaccountname -eq "administrator"}
```
> [!NOTE]
> Use of this command requires the RSAT-AD-PowerShell feature.
> [!TIP]
> In addition to the Windows PowerShell command above, information about the locally logged on user and group membership can be found using: `WHOAMI /ALL`. This doesn't require the use of additional features.
In the example below, the user wishes to add a domain SID-based protector to the previously encrypted operating system volume. The user knows the SID for the user account or group they wish to add and uses the following command:
```powershell
Add-BitLockerKeyProtector C: -ADAccountOrGroupProtector -ADAccountOrGroup "<SID>"
```
> [!NOTE]
> Active Directory-based protectors are normally used to unlock Failover Cluster-enabled volumes.
## Checking BitLocker status
To check the BitLocker status of a particular volume, administrators can look at the status of the drive in the BitLocker control panel applet, Windows Explorer, `manage-bde.exe` command-line tool, or Windows PowerShell cmdlets. Each option offers different levels of detail and ease of use. We'll look at each of the available methods in the following section.
### Checking BitLocker status with the control panel
Checking BitLocker status with the control panel is the most common method used by most users. Once opened, the status for each volume is displayed next to the volume description and drive letter. Available status return values with the control panel include:
| Status | Description |
| - | - |
| **On**|BitLocker is enabled for the volume |
| **Off**| BitLocker isn't enabled for the volume |
| **Suspended** | BitLocker is suspended and not actively protecting the volume |
| **Waiting for Activation**| BitLocker is enabled with a clear protector key and requires further action to be fully protected|
If a drive is pre-provisioned with BitLocker, a status of "Waiting for Activation" displays with a yellow exclamation icon on the volume. This status means that there was only a clear protector used when encrypting the volume. In this case, the volume isn't in a protected state and needs to have a secure key added to the volume before the drive is fully protected. Administrators can use the control panel, `manage-bde.exe` tool, or WMI APIs to add an appropriate key protector. Once complete, the control panel will update to reflect the new status.
Using the control panel, administrators can choose **Turn on BitLocker** to start the BitLocker Drive Encryption wizard and add a protector, like PIN for an operating system volume (or password if no TPM exists), or a password or smart card protector to a data volume.
The drive security window displays prior to changing the volume status. Selecting **Activate BitLocker** will complete the encryption process.
Once BitLocker protector activation is completed, the completion notice is displayed.
### Checking BitLocker status with `manage-bde.exe`
Administrators who prefer a command-line interface can utilize `manage-bde.exe` to check volume status. Manage-bde is capable of returning more information about the volume than the graphical user interface tools in the control panel. For example, `manage-bde.exe` can display the BitLocker version in use, the encryption type, and the protectors associated with a volume.
To check the status of a volume using `manage-bde.exe`, use the following command:
```powershell
manage-bde.exe -status <volume>
```
> [!NOTE]
> If no volume letter is associated with the -status command, all volumes on the computer display their status.
### Checking BitLocker status with Windows PowerShell
Windows PowerShell commands offer another way to query BitLocker status for volumes. Like `manage-bde.exe`, Windows PowerShell includes the advantage of being able to check the status of a volume on a remote computer.
Using the Get-BitLockerVolume cmdlet, each volume on the system displays its current BitLocker status. To get information that is more detailed on a specific volume, use the following command:
```powershell
Get-BitLockerVolume <volume> -Verbose | fl
```
This command displays information about the encryption method, volume type, key protectors, and more.
### Provisioning BitLocker during operating system deployment
Administrators can enable BitLocker prior to operating system deployment from the Windows Pre-installation environment. Enabling BitLocker prior to the operating system deployment is done with a randomly generated clear key protector applied to the formatted volume and by encrypting the volume prior to running the Windows setup process. If the encryption uses the **Used Disk Space Only** option described later in this document, this step takes only a few seconds and incorporates well into regular deployment processes.
### Decrypting BitLocker volumes
Decrypting volumes removes BitLocker and any associated protectors from the volumes. Decryption should occur when protection is no longer required. BitLocker decryption shouldn't occur as a troubleshooting step. BitLocker can be removed from a volume using the BitLocker control panel applet, `manage-bde.exe`, or Windows PowerShell cmdlets. We'll discuss each method further below.
### Decrypting volumes using the BitLocker control panel applet
BitLocker decryption using the control panel is done using a wizard. The control panel can be called from Windows Explorer or by opening it directly. After opening the BitLocker control panel, users will select the **Turn off BitLocker** option to begin the process.
After selecting the **Turn off BitLocker** option, the user chooses to continue by clicking the confirmation dialog. With **Turn off BitLocker** confirmed, the drive decryption process begins and reports status to the control panel.
The control panel doesn't report decryption progress but displays it in the notification area of the task bar. Selecting the notification area icon will open a modal dialog with progress.
Once decryption is complete, the drive updates its status in the control panel and becomes available for encryption.
### Decrypting volumes using the `manage-bde.exe` command-line interface
Decrypting volumes using `manage-bde.exe` is straightforward. Decryption with `manage-bde.exe` offers the advantage of not requiring user confirmation to start the process. Manage-bde uses the -off command to start the decryption process. A sample command for decryption is:
```powershell
manage-bde.exe -off C:
```
This command disables protectors while it decrypts the volume and removes all protectors when decryption is complete. If users wish to check the status of the decryption, they can use the following command:
```powershell
manage-bde.exe -status C:
```
### Decrypting volumes using the BitLocker Windows PowerShell cmdlets
Decryption with Windows PowerShell cmdlets is straightforward, similar to `manage-bde.exe`. Windows PowerShell offers the ability to decrypt multiple drives in one pass. In the example below, the user has three encrypted volumes, which they wish to decrypt.
Using the Disable-BitLocker command, they can remove all protectors and encryption at the same time without the need for more commands. An example of this command is:
```powershell
Disable-BitLocker
```
If a user didn't want to input each mount point individually, using the `-MountPoint` parameter in an array can sequence the same command into one line without requiring additional user input. An example command is:
```powershell
Disable-BitLocker -MountPoint E:,F:,G:
```
## Related articles
- [Prepare your organization for BitLocker: Planning and policies](prepare-your-organization-for-bitlocker-planning-and-policies.md)
- [BitLocker recovery guide](bitlocker-recovery-guide-plan.md)
- [BitLocker: How to enable Network Unlock](bitlocker-how-to-enable-network-unlock.md)
- [BitLocker overview](bitlocker-overview.md)

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---
title: BitLocker Countermeasures
description: Windows uses technologies including TPM, Secure Boot, Trusted Boot, and Early Launch Anti-malware (ELAM) to protect against attacks on the BitLocker encryption key.
ms.topic: conceptual
ms.date: 11/08/2022
---
# BitLocker Countermeasures
Windows uses technologies including trusted platform module (TPM), secure boot, and measured boot to help protect BitLocker encryption keys against attacks. BitLocker is part of a strategic approach to securing data against offline attacks through encryption technology. Data on a lost or stolen computer is vulnerable. For example, there could be unauthorized access, either by running a software attack tool against the computer or by transferring the computer's hard disk to a different computer.
BitLocker helps mitigate unauthorized data access on lost or stolen computers before the authorized operating system is started. This mitigation is done by:
- **Encrypting volumes on a computer.** For example, BitLocker can be turned on for the operating system volume, a volume on a fixed drive. or removable data drive (such as a USB flash drive, SD card, etc.) Turning on BitLocker for the operating system volume encrypts all system files on the volume, including the paging files and hibernation files. The only exception is for the System partition, which includes the Windows Boot Manager and minimal boot collateral required for decryption of the operating system volume after the key is unsealed.
- **Ensuring the integrity of early boot components and boot configuration data.** On devices that have a TPM version 1.2 or higher, BitLocker uses the enhanced security capabilities of the TPM to make data accessible only if the computer's BIOS firmware code and configuration, original boot sequence, boot components, and BCD configuration all appear unaltered and the encrypted disk is located in the original computer. On systems that use TPM PCR[7], BCD setting changes deemed safe are permitted to improve usability.
The next sections provide more details about how Windows protects against various attacks on the BitLocker encryption keys in Windows 11, Windows 10, Windows 8.1, and Windows 8.
For more information about how to enable the best overall security configuration for devices beginning with Windows 10 version 1803, see [Standards for a highly secure Windows device](/windows-hardware/design/device-experiences/oem-highly-secure).
## Protection before startup
Before Windows starts, security features implemented as part of the device hardware and firmware must be relied on, including TPM and secure boot. Fortunately, many modern computers feature a TPM and secure boot.
### Trusted Platform Module
A trusted platform module (TPM) is a microchip designed to provide basic security-related functions, primarily involving encryption keys. On some platforms, TPM can alternatively be implemented as a part of secure firmware. BitLocker binds encryption keys with the TPM to ensure that a computer hasn't been tampered with while the system was offline. For more info about TPM, see [Trusted Platform Module](/windows/device-security/tpm/trusted-platform-module-overview).
### UEFI and secure boot
Unified Extensible Firmware Interface (UEFI) is a programmable boot environment that initializes devices and starts the operating system's bootloader.
The UEFI specification defines a firmware execution authentication process called [Secure Boot](../secure-the-windows-10-boot-process.md). Secure Boot blocks untrusted firmware and bootloaders (signed or unsigned) from being able to start on the system.
By default, BitLocker provides integrity protection for Secure Boot by utilizing the TPM PCR[7] measurement. An unauthorized EFI firmware, EFI boot application, or bootloader can't run and acquire the BitLocker key.
### BitLocker and reset attacks
To defend against malicious reset attacks, BitLocker uses the TCG Reset Attack Mitigation, also known as MOR bit (Memory Overwrite Request), before extracting keys into memory.
>[!NOTE]
>This does not protect against physical attacks where an attacker opens the case and attacks the hardware.
## Security policies
The next sections cover pre-boot authentication and DMA policies that can provide additional protection for BitLocker.
### Pre-boot authentication
Pre-boot authentication with BitLocker is a policy setting that requires the use of either user input, such as a PIN, a startup key, or both to authenticate prior to making the contents of the system drive accessible. The Group Policy setting is [Require additional authentication at startup](./bitlocker-group-policy-settings.md) and the corresponding setting in the [BitLocker CSP](/windows/client-management/mdm/bitlocker-csp) is SystemDrivesRequireStartupAuthentication.
BitLocker accesses and stores the encryption keys in memory only after pre-boot authentication is completed. If Windows can't access the encryption keys, the device can't read or edit the files on the system drive. The only option for bypassing pre-boot authentication is entering the recovery key.
Pre-boot authentication is designed to prevent the encryption keys from being loaded to system memory without the trusted user supplying another authentication factor such as a PIN or startup key. This feature helps mitigate DMA and memory remanence attacks.
On computers with a compatible TPM, operating system drives that are BitLocker-protected can be unlocked in four ways:
- **TPM-only.** Using TPM-only validation doesn't require any interaction with the user to unlock and provide access to the drive. If the TPM validation succeeds, the user sign-in experience is the same as a standard sign-in. If the TPM is missing or changed or if BitLocker detects changes to the BIOS or UEFI code or configuration, critical operating system startup files, or the boot configuration, BitLocker enters recovery mode, and the user must enter a recovery password to regain access to the data. This option is more convenient for sign-in but less secure than the other options, which require an additional authentication factor.
- **TPM with startup key.** In addition to the protection that the TPM-only provides, part of the encryption key is stored on a USB flash drive, referred to as a startup key. Data on the encrypted volume can't be accessed without the startup key.
- **TPM with PIN.** In addition to the protection that the TPM provides, BitLocker requires that the user enters a PIN. Data on the encrypted volume can't be accessed without entering the PIN. TPMs also have [anti-hammering protection](/windows/security/hardware-protection/tpm/tpm-fundamentals#anti-hammering) that is designed to prevent brute force attacks that attempt to determine the PIN.
- **TPM with startup key and PIN.** In addition to the core component protection that the TPM-only provides, part of the encryption key is stored on a USB flash drive, and a PIN is required to authenticate the user to the TPM. This configuration provides multifactor authentication so that if the USB key is lost or stolen, it can't be used for access to the drive, because the correct PIN is also required.
In the following group policy example, TPM + PIN is required to unlock an operating system drive:
![Pre-boot authentication setting in Group Policy.](images/pre-boot-authentication-group-policy.png)
Pre-boot authentication with a PIN can mitigate an attack vector for devices that use a bootable eDrive because an exposed eDrive bus can allow an attacker to capture the BitLocker encryption key during startup. Pre-boot authentication with a PIN can also mitigate DMA port attacks during the window of time between when BitLocker unlocks the drive and Windows boots to the point that Windows can set any port-related policies that have been configured.
On the other hand, Pre-boot authentication-prompts can be inconvenient to users. In addition, users who forget their PIN or lose their startup key are denied access to their data until they can contact their organization's support team to obtain a recovery key. Pre-boot authentication can also make it more difficult to update unattended desktops and remotely administered servers because a PIN needs to be entered when a computer reboots or resumes from hibernation.
To address these issues, [BitLocker Network Unlock](./bitlocker-how-to-enable-network-unlock.md) can be deployed. Network Unlock allows systems within the physical enterprise security perimeter that meet the hardware requirements and have BitLocker enabled with TPM+PIN to boot into Windows without user intervention. It requires direct ethernet connectivity to an enterprise Windows Deployment Services (WDS) server.
### Protecting Thunderbolt and other DMA ports
There are a few different options to protect DMA ports, such as Thunderbolt&trade;3. Beginning with Windows 10 version 1803, new Intel-based devices have kernel protection against DMA attacks via Thunderbolt&trade; 3 ports enabled by default. This Kernel DMA Protection is available only for new systems beginning with Windows 10 version 1803, as it requires changes in the system firmware and/or BIOS.
You can use the System Information desktop app `MSINFO32.exe` to check if a device has kernel DMA protection enabled:
![Kernel DMA protection.](images/kernel-dma-protection.png)
If kernel DMA protection isn't enabled, follow these steps to protect Thunderbolt&trade; 3 enabled ports:
1. Require a password for BIOS changes
2. Intel Thunderbolt Security must be set to User Authorization in BIOS settings. Refer to [Intel Thunderbolt&trade; 3 and Security on Microsoft Windows&reg; 10 Operating System documentation](https://thunderbolttechnology.net/security/Thunderbolt%203%20and%20Security.pdf)
3. Additional DMA security may be added by deploying policy (beginning with Windows 10 version 1607 or Windows 11):
- MDM: [DataProtection/AllowDirectMemoryAccess](/windows/client-management/mdm/policy-csp-dataprotection#dataprotection-allowdirectmemoryaccess) policy
- Group Policy: [Disable new DMA devices when this computer is locked](./bitlocker-group-policy-settings.md#disable-new-dma-devices-when-this-computer-is-locked) (This setting isn't configured by default.)
For Thunderbolt v1 and v2 (DisplayPort Connector), refer to the **Thunderbolt Mitigation** section in [Blocking the SBP-2 driver and Thunderbolt controllers to reduce 1394 DMA and Thunderbolt DMA threats to BitLocker](https://support.microsoft.com/help/2516445/blocking-the-sbp-2-driver-and-thunderbolt-controllers-to-reduce-1394-d). For SBP-2 and 1394 (also known as Firewire), refer to the **SBP-2 Mitigation** section in [Blocking the SBP-2 driver and Thunderbolt controllers to reduce 1394 DMA and Thunderbolt DMA threats to BitLocker](https://support.microsoft.com/help/2516445/blocking-the-sbp-2-driver-and-thunderbolt-controllers-to-reduce-1394-d).
## Attack countermeasures
This section covers countermeasures for specific types of attacks.
### Bootkits and rootkits
A physically present attacker might attempt to install a bootkit or rootkit-like piece of software into the boot chain in an attempt to steal the BitLocker keys. The TPM should observe this installation via PCR measurements, and the BitLocker key won't be released.
> [!NOTE]
> BitLocker protects against this attack by default.
A BIOS password is recommended for defense-in-depth in case a BIOS exposes settings that may weaken the BitLocker security promise. Intel Boot Guard and AMD Hardware Verified Boot support stronger implementations of Secure Boot that provide additional resilience against malware and physical attacks. Intel Boot Guard and AMD Hardware Verified Boot are part of platform boot verification [standards for a highly secure Windows device](/windows-hardware/design/device-experiences/oem-highly-secure).
### Brute force attacks against a PIN
Require TPM + PIN for anti-hammering protection.
### DMA attacks
See [Protecting Thunderbolt and other DMA ports](#protecting-thunderbolt-and-other-dma-ports) earlier in this article.
### Paging file, crash dump, and Hyberfil.sys attacks
These files are secured on an encrypted volume by default when BitLocker is enabled on OS drives. It also blocks automatic or manual attempts to move the paging file.
### Memory remanence
Enable secure boot and mandatorily prompt a password to change BIOS settings. For customers requiring protection against these advanced attacks, configure a TPM+PIN protector, disable Standby power management, and shut down or hibernate the device before it leaves the control of an authorized user.
### Tricking BitLocker to pass the key to a rogue operating system
An attacker might modify the boot manager configuration database (BCD) which is stored on a non-encrypted partition and add an entry point to a rogue operating system on a different partition. During the boot process, BitLocker code will make sure that the operating system that the encryption key obtained from the TPM is given to, is cryptographically verified to be the intended recipient. Because this strong cryptographic verification already exists, we don't recommend storing a hash of a disk partition table in Platform Configuration Register (PCR) 5.
An attacker might also replace the entire operating system disk while preserving the platform hardware and firmware and could then extract a protected BitLocker key blob from the metadata of the victim OS partition. The attacker could then attempt to unseal that BitLocker key blob by calling the TPM API from an operating system under their control. This will not succeed because when Windows seals the BitLocker key to the TPM, it does it with a PCR 11 value of 0, and to successfully unseal the blob, PCR 11 in the TPM must have a value of 0. However, when the boot manager passes the control to any boot loader (legitimate or rogue) it always changes PCR 11 to a value of 1. Since the PCR 11 value is guaranteed to be different after exiting the boot manager, the attacker can't unlock the BitLocker key.
## Attacker countermeasures
The following sections cover mitigations for different types of attackers.
### Attacker without much skill or with limited physical access
Physical access may be limited by a form factor that doesn't expose buses and memory. For example, there are no external DMA-capable ports, no exposed screws to open the chassis, and memory is soldered to the mainboard.
This attacker of opportunity doesn't use destructive methods or sophisticated forensics hardware/software.
Mitigation:
- Pre-boot authentication set to TPM only (the default)
### Attacker with skill and lengthy physical access
Targeted attack with plenty of time; this attacker will open the case, will solder, and will use sophisticated hardware or software.
Mitigation:
- Pre-boot authentication set to TPM with a PIN protector (with a sophisticated alphanumeric PIN [enhanced pin] to help the TPM anti-hammering mitigation).
-And-
- Disable Standby power management and shut down or hibernate the device before it leaves the control of an authorized user. This configuration can be set using the following Group Policy:
- *Computer Configuration* > *Policies* > *Administrative Templates* > *Windows Components* > *File Explorer* > **Show hibernate in the power options menu**
- *Computer Configuration* > *Policies* > *Administrative Templates* > *Power Management* > *Sleep Settings* > **Allow standby states (S1-S3) when sleeping (plugged in)**
- *Computer Configuration* > *Policies* > *Administrative Templates* > *Power Management* > *Sleep Settings* > **Allow standby states (S1-S3) when sleeping (on battery)**
> [!IMPORTANT]
> These settings are **not configured** by default.
For some systems, bypassing TPM-only may require opening the case, and may require soldering, but could possibly be done for a reasonable cost. Bypassing a TPM with a PIN protector would cost much more, and require brute forcing the PIN. With a sophisticated enhanced PIN, it could be nearly impossible. The Group Policy setting for [enhanced PIN](./bitlocker-group-policy-settings.md) is:
- *Computer Configuration* > *Policies* > *Administrative Templates* > *Windows Components* > *BitLocker Drive Encryption* > *Operating System Drives* > **Allow enhanced PINs for startup**
> [!IMPORTANT]
> This setting is **not configured** by default.
For secure administrative workstations, Microsoft recommends a TPM with PIN protector and to disable Standby power management and shut down or hibernate the device.
## Related articles
- [Blocking the SBP-2 driver and Thunderbolt controllers to reduce 1394 DMA and Thunderbolt DMA threats to BitLocker](https://support.microsoft.com/help/2516445/blocking-the-sbp-2-driver-and-thunderbolt-controllers-to-reduce-1394-d)
- [BitLocker Group Policy settings](./bitlocker-group-policy-settings.md)
- [BitLocker CSP](/windows/client-management/mdm/bitlocker-csp)
- [Winlogon automatic restart sign-on (ARSO)](/windows-server/identity/ad-ds/manage/component-updates/winlogon-automatic-restart-sign-on--arso-)

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### YamlMime:FAQ
metadata:
title: BitLocker deployment and administration FAQ (Windows 10)
description: Browse frequently asked questions about BitLocker deployment and administration, such as, "Can BitLocker deployment be automated in an enterprise environment?"
ms.prod: windows-client
ms.technology: itpro-security
author: frankroj
ms.author: frankroj
manager: aaroncz
ms.topic: faq
ms.date: 11/08/2022
ms.custom: bitlocker
title: BitLocker frequently asked questions (FAQ)
summary: |
sections:
- name: Ignored
questions:
- question: Can BitLocker deployment be automated in an enterprise environment?
answer: |
Yes, the deployment and configuration of both BitLocker and the TPM can be automated using either WMI or Windows PowerShell scripts. Which method is chosen to implement the automation depends on the environment. `Manage-bde.exe` can also be used to locally or remotely configure BitLocker. For more info about writing scripts that use the BitLocker WMI providers, see [BitLocker Drive Encryption Provider](/windows/win32/secprov/bitlocker-drive-encryption-provider). For more info about using Windows PowerShell cmdlets with BitLocker Drive Encryption, see [BitLocker Cmdlets in Windows PowerShell](/powershell/module/bitlocker/index?view=win10-ps).
- question: Can BitLocker encrypt more than just the operating system drive?
answer: Yes.
- question: Is there a noticeable performance impact when BitLocker is enabled on a computer?
answer: Typically, there's a small performance overhead, often in single-digit percentages, which is relative to the throughput of the storage operations on which it needs to operate.
- question: How long will initial encryption take when BitLocker is turned on?
answer: |
Although BitLocker encryption occurs in the background while a user continues to work with the system remaining usable, encryption times vary depending on the type of drive that is being encrypted, the size of the drive, and the speed of the drive. If encrypting large drives, encryption may want to be scheduled during times when the drive isn't being used.
When BitLocker is enabled, BitLocker can also be set to encrypt the entire drive or just the used space on the drive. On a new hard drive, encrypting just the used spaced can be considerably faster than encrypting the entire drive. When this encryption option is selected, BitLocker automatically encrypts data as it is saved, ensuring that no data is stored unencrypted.
- question: What happens if the computer is turned off during encryption or decryption?
answer: If the computer is turned off or goes into hibernation, the BitLocker encryption and decryption process will resume where it stopped the next time Windows starts. BitLocker resuming encryption or decryption is true even if the power is suddenly unavailable.
- question: Does BitLocker encrypt and decrypt the entire drive all at once when reading and writing data?
answer: No, BitLocker doesn't encrypt and decrypt the entire drive when reading and writing data. The encrypted sectors in the BitLocker-protected drive are decrypted only as they're requested from system read operations. Blocks that are written to the drive are encrypted before the system writes them to the physical disk. No unencrypted data is ever stored on a BitLocker-protected drive.
- question: How can I prevent users on a network from storing data on an unencrypted drive?
answer: |
Group Policy settings can be configured to require that data drives be BitLocker-protected before a BitLocker-protected computer can write data to them. For more info, see [BitLocker Group Policy settings](bitlocker-group-policy-settings.md).
When these policy settings are enabled, the BitLocker-protected operating system will mount any data drives that aren't protected by BitLocker as read-only.
- question: What is Used Disk Space Only encryption?
answer: |
BitLocker in Windows 10 lets users choose to encrypt just their data. Although it's not the most secure way to encrypt a drive, this option can reduce encryption time by more than 99 percent, depending on how much data that needs to be encrypted. For more information, see [Used Disk Space Only encryption](bitlocker-device-encryption-overview-windows-10.md#used-disk-space-only-encryption).
- question: What system changes would cause the integrity check on my operating system drive to fail?
answer: |
The following types of system changes can cause an integrity check failure and prevent the TPM from releasing the BitLocker key to decrypt the protected operating system drive:
- Moving the BitLocker-protected drive into a new computer.
- Installing a new motherboard with a new TPM.
- Turning off, disabling, or clearing the TPM.
- Changing any boot configuration settings.
- Changing the BIOS, UEFI firmware, master boot record, boot sector, boot manager, option ROM, or other early boot components or boot configuration data.
- question: What causes BitLocker to start into recovery mode when attempting to start the operating system drive?
answer: |
Because BitLocker is designed to protect computers from numerous attacks, there are numerous reasons why BitLocker could start in recovery mode.
For example:
- Changing the BIOS boot order to boot another drive in advance of the hard drive.
- Adding or removing hardware, such as inserting a new card in the computer.
- Removing, inserting, or completely depleting the charge on a smart battery on a portable computer.
In BitLocker, recovery consists of decrypting a copy of the volume master key using either a recovery key stored on a USB flash drive or a cryptographic key derived from a recovery password.
The TPM isn't involved in any recovery scenarios, so recovery is still possible if the TPM fails boot component validation, malfunctions, or is removed.
- question: What can prevent BitLocker from binding to PCR 7?
answer: BitLocker can be prevented from binding to PCR 7 if a non-Windows OS booted prior to Windows, or if Secure Boot isn't available to the device, either because it has been disabled or the hardware doesn't support it.
- question: Can I swap hard disks on the same computer if BitLocker is enabled on the operating system drive?
answer: Yes, multiple hard disks can be swapped on the same computer if BitLocker is enabled, but only if the hard disks were BitLocker-protected on the same computer. The BitLocker keys are unique to the TPM and the operating system drive. If a backup operating system or data drive needs to be prepared in case of a disk failure, make sure that they were matched with the correct TPM. Different hard drives can also be configured for different operating systems and then enable BitLocker on each one with different authentication methods (such as one with TPM-only and one with TPM+PIN) without any conflicts.
- question: Can I access my BitLocker-protected drive if I insert the hard disk into a different computer?
answer: Yes, if the drive is a data drive, it can be unlocked from the **BitLocker Drive Encryption** Control Panel item by using a password or smart card. If the data drive was configured for automatic unlock only, it will need to be unlocked by using the recovery key. The encrypted hard disk can be unlocked by a data recovery agent (if one was configured) or it can be unlocked by using the recovery key.
- question: Why is **Turn BitLocker on** not available when I right-click a drive?
answer: Some drives can't be encrypted with BitLocker. Reasons a drive can't be encrypted include insufficient disk size, an incompatible file system, if the drive is a dynamic disk, or a drive is designated as the system partition. By default, the system drive (or system partition) is hidden from display. However, if it isn't created as a hidden drive when the operating system was installed due to a custom installation process, that drive might be displayed but can't be encrypted.
- question: What type of disk configurations are supported by BitLocker?
answer: Any number of internal, fixed data drives can be protected with BitLocker. On some versions ATA and SATA-based, direct-attached storage devices are also supported.

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---
title: BitLocker deployment comparison
description: This article shows the BitLocker deployment comparison chart.
ms.topic: conceptual
ms.date: 11/08/2022
---
# BitLocker deployment comparison
This article depicts the BitLocker deployment comparison chart.
## BitLocker deployment comparison chart
| Requirements |Microsoft Intune |Microsoft Configuration Manager |Microsoft BitLocker Administration and Monitoring (MBAM) |
|---------|---------|---------|---------|
|*Minimum client operating system version* |Windows 11 and Windows 10 | Windows 11, Windows 10, and Windows 8.1 | Windows 7, Windows 8, Windows 8.1, Windows 10, Windows 10 IoT, and Windows 11 |
|*Supported Windows SKUs* | Enterprise, Pro, Education | Enterprise, Pro, Education | Enterprise |
|*Minimum Windows version* |1909 | None | None |
|*Supported domain-joined status* | Microsoft Azure Active Directory (Azure AD) joined, hybrid Azure AD joined | Active Directory-joined, hybrid Azure AD joined | Active Directory-joined |
|*Permissions required to manage policies* | Endpoint security manager or custom | Full administrator or custom | Domain Admin or Delegated GPO access |
|*Cloud or on premises* | Cloud | On premises | On premises |
|Server components required? | | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Additional agent required?* | No (device enrollment only) | Configuration Manager client | MBAM client |
|*Administrative plane* | Microsoft Intune admin center | Configuration Manager console | Group Policy Management Console and MBAM sites |
|*Administrative portal installation required* | | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Compliance reporting capabilities* | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Force encryption* | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Encryption for storage cards (mobile)* | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | |
|*Allow recovery password* | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Manage startup authentication* | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Select cipher strength and algorithms for fixed drives* | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Select cipher strength and algorithms for removable drives* | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Select cipher strength and algorithms for operating environment drives* | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Standard recovery password storage location* | Azure AD or Active Directory | Configuration Manager site database | MBAM database |
|*Store recovery password for operating system and fixed drives to Azure AD or Active Directory* | Yes (Active Directory and Azure AD) | Yes (Active Directory only) | Yes (Active Directory only) |
|*Customize preboot message and recovery link* | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Allow/deny key file creation* | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Deny Write permission to unprotected drives* | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Can be administered outside company network* | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | |
|*Support for organization unique IDs* | | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Self-service recovery* | Yes (through Azure AD or Company Portal app) | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Recovery password rotation for fixed and operating environment drives* | Yes (Windows 10, version 1909 and later) | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Wait to complete encryption until recovery information is backed up to Azure AD* | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | | |
|*Wait to complete encryption until recovery information is backed up to Active Directory* | | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Allow or deny Data Recovery Agent* | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Unlock a volume using certificate with custom object identifier* | | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Prevent memory overwrite on restart* | | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Configure custom Trusted Platform Module Platform Configuration Register profiles* | | | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |
|*Manage auto-unlock functionality* | | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: | :::image type="content" source="images/yes-icon.png" alt-text="supported."::: |

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---
title: Overview of BitLocker Device Encryption in Windows
description: This article provides an overview of how BitLocker Device Encryption can help protect data on devices running Windows.
ms.collection:
- highpri
- tier1
ms.topic: conceptual
ms.date: 11/08/2022
---
# Overview of BitLocker device encryption
This article explains how BitLocker Device Encryption can help protect data on devices running Windows. See [BitLocker](bitlocker-overview.md) for a general overview and list of articles.
When users travel, their organization's confidential data goes with them. Wherever confidential data is stored, it must be protected against unauthorized access. Windows has a long history of providing at-rest data-protection solutions that guard against nefarious attackers, beginning with the Encrypting File System in the Windows 2000 operating system. More recently, BitLocker has provided encryption for full drives and portable drives. Windows consistently improves data protection by improving existing options and providing new strategies.
## Data Protection in Windows 11, Windows 10, and Windows 7
The below table lists specific data-protection concerns and how they're addressed in Windows 11, Windows 10, and Windows 7.
| Windows 7 | Windows 11 and Windows 10 |
|---|---|
| When BitLocker is used with a PIN to protect startup, PCs such as kiosks can't be restarted remotely. | Modern Windows devices are increasingly protected with BitLocker Device Encryption out of the box and support SSO to seamlessly protect the BitLocker encryption keys from cold boot attacks.<br><br>Network Unlock allows PCs to start automatically when connected to the internal network. |
| When BitLocker is enabled, the provisioning process can take several hours. | BitLocker pre-provisioning, encrypting hard drives, and Used Space Only encryption allow administrators to enable BitLocker quickly on new computers. |
| There's no support for using BitLocker with self-encrypting drives (SEDs). | BitLocker supports offloading encryption to encrypted hard drives. |
| Administrators have to use separate tools to manage encrypted hard drives. | BitLocker supports encrypted hard drives with onboard encryption hardware built in, which allows administrators to use the familiar BitLocker administrative tools to manage them. |
| Encrypting a new flash drive can take more than 20 minutes. | Used Space Only encryption in BitLocker To Go allows users to encrypt removable data drives in seconds. |
| BitLocker could require users to enter a recovery key when system configuration changes occur. | BitLocker requires the user to enter a recovery key only when disk corruption occurs or when the PIN or password is lost. |
| Users need to enter a PIN to start the PC, and then their password to sign in to Windows. | Modern Windows devices are increasingly protected with BitLocker Device Encryption out of the box and support SSO to help protect the BitLocker encryption keys from cold boot attacks. |
## Prepare for drive and file encryption
The best type of security measures is transparent to the user during implementation and use. Every time there's a possible delay or difficulty because of a security feature, there's a strong likelihood that users will try to bypass security. This situation is especially true for data protection, and that's a scenario that organizations need to avoid. Whether planning to encrypt entire volumes, removable devices, or individual files, Windows 11 and Windows 10 meet these needs by providing streamlined, usable solutions. In fact, several steps can be taken in advance to prepare for data encryption and make the deployment quick and smooth.
### TPM pre-provisioning
In Windows 7, preparing the TPM offered a few challenges:
- Turning on the TPM required going into the BIOS or UEFI firmware of the device. Turning on the TPM at the device requires someone to either physically go into the BIOS or UEFI firmware settings of the device to turn on the TPM, or to install a driver in Windows to turn on the TPM from within Windows.
- When the TPM is enabled, it may require one or more restarts.
This made preparing the TPM in Windows 7 problematic. If IT staff are provisioning new PCs, they can handle the required steps for preparing a TPM. However, if BitLocker needed to be enabled on devices that are already in users' hands, those users would probably struggle with the technical challenges. The user would then either call to IT for support or leave BitLocker disabled.
Microsoft includes instrumentation in Windows 11 and Windows 10 that enable the operating system to fully manage the TPM. There's no need to go into the BIOS, and all scenarios that required a restart have been eliminated.
## Deploy hard drive encryption
BitLocker is capable of encrypting entire hard drives, including both system and data drives. BitLocker pre-provisioning can drastically reduce the time required to provision new PCs with BitLocker enabled. With Windows 11 and Windows 10, administrators can turn on BitLocker and the TPM from within the Windows Pre-installation Environment before they install Windows or as part of an automated deployment task sequence without any user interaction. Combined with Used Disk Space Only encryption and a mostly empty drive (because Windows isn't yet installed), it takes only a few seconds to enable BitLocker.
With earlier versions of Windows, administrators had to enable BitLocker after Windows had been installed. Although this process could be automated, BitLocker would need to encrypt the entire drive, a process that could take anywhere from several hours to more than a day depending on drive size and performance, which delayed deployment. Microsoft has improved this process through multiple features in Windows 11 and Windows 10.
## BitLocker Device Encryption
Beginning in Windows 8.1, Windows automatically enables BitLocker Device Encryption on devices that support Modern Standby. With Windows 11 and Windows 10, Microsoft offers BitLocker Device Encryption support on a much broader range of devices, including those devices that are Modern Standby, and devices that run Home edition of Windows 10 or Windows 11.
Microsoft expects that most devices in the future will pass the requirements for BitLocker Device Encryption that will make BitLocker Device Encryption pervasive across modern Windows devices. BitLocker Device Encryption further protects the system by transparently implementing device-wide data encryption.
Unlike a standard BitLocker implementation, BitLocker Device Encryption is enabled automatically so that the device is always protected. The following list outlines how BitLocker Device Encryption is enabled automatically:
- When a clean installation of Windows 11 or Windows 10 is completed and the out-of-box experience is finished, the computer is prepared for first use. As part of this preparation, BitLocker Device Encryption is initialized on the operating system drive and fixed data drives on the computer with a clear key that is the equivalent of standard BitLocker suspended state. In this state, the drive is shown with a warning icon in Windows Explorer. The yellow warning icon is removed after the TPM protector is created and the recovery key is backed up, as explained in the following bullet points.
- If the device isn't domain joined, a Microsoft account that has been granted administrative privileges on the device is required. When the administrator uses a Microsoft account to sign in, the clear key is removed, a recovery key is uploaded to the online Microsoft account, and a TPM protector is created. Should a device require the recovery key, the user will be guided to use an alternate device and navigate to a recovery key access URL to retrieve the recovery key by using their Microsoft account credentials.
- If the user uses a domain account to sign in, the clear key isn't removed until the user joins the device to a domain, and the recovery key is successfully backed up to Active Directory Domain Services (AD DS). The following Group Policy settings must be enabled for the recovery key to be backed up to AD DS:
*Computer Configuration* > *Administrative Templates* > *Windows Components* > *BitLocker Drive Encryption* > *Operating System Drives* > **Do not enable BitLocker until recovery information is stored in AD DS for operating system drives**
With this configuration, the recovery password is created automatically when the computer joins the domain, and then the recovery key is backed up to AD DS, the TPM protector is created, and the clear key is removed.
- Similar to signing in with a domain account, the clear key is removed when the user signs in to an Azure AD account on the device. As described in the bullet point above, the recovery password is created automatically when the user authenticates to Azure AD. Then, the recovery key is backed up to Azure AD, the TPM protector is created, and the clear key is removed.
Microsoft recommends automatically enabling BitLocker Device Encryption on any systems that support it. However, the automatic BitLocker Device Encryption process can be prevented by changing the following registry setting:
- **Subkey**: `HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\BitLocker`
- **Type**: `REG_DWORD`
- **Value**: `PreventDeviceEncryption` equal to `1` (True)
Administrators can manage domain-joined devices that have BitLocker Device Encryption enabled through Microsoft BitLocker Administration and Monitoring (MBAM). In this case, BitLocker Device Encryption automatically makes additional BitLocker options available. No conversion or encryption is required, and MBAM can manage the full BitLocker policy set if any configuration changes are required.
> [!NOTE]
> BitLocker Device Encryption uses the XTS-AES 128-bit encryption method. If a different encryption method and/or cipher strength is needed but the device is already encrypted, it must first be decrypted before the new encryption method and/or cipher strength can be applied. After the device has been decrypted, different BitLocker settings can be applied.
## Used Disk Space Only encryption
BitLocker in earlier Windows versions could take a long time to encrypt a drive because it encrypted every byte on the volume including areas that didn't have data. Encrypting every byte on the volume including areas that didn't have data is known as full disk encryption. Full disk encryption is still the most secure way to encrypt a drive, especially if a drive has previously contained confidential data that has since been moved or deleted. If a drive previously had confidential data that has been moved or deleted, traces of the confidential data could remain on portions of the drive marked as unused.
To reduce encryption time, BitLocker in Windows 11 and Windows 10 let users choose to encrypt just the areas of the disk that contain data. Areas of the disk that don't contain data and are empty won't be encrypted. Any new data is encrypted as it's created. Depending on the amount of data on the drive, this option can reduce the initial encryption time by more than 99 percent.
Exercise caution when encrypting only used space on an existing volume on which confidential data may have already been stored in an unencrypted state. When using used space encryption, sectors where previously unencrypted data are stored can be recovered through disk-recovery tools until they're overwritten by new encrypted data. In contrast, encrypting only used space on a brand-new volume can significantly decrease deployment time without the security risk because all new data will be encrypted as it's written to the disk.
## Encrypted hard drive support
SEDs have been available for years, but Microsoft couldn't support their use with some earlier versions of Windows because the drives lacked important key management features. Microsoft worked with storage vendors to improve the hardware capabilities, and now BitLocker supports the next generation of SEDs, which are called encrypted hard drives.
Encrypted hard drives provide onboard cryptographic capabilities to encrypt data on drives. This feature improves both drive and system performance by offloading cryptographic calculations from the PC's processor to the drive itself. Data is rapidly encrypted by the drive by using dedicated, purpose-built hardware. If planning to use whole-drive encryption with Windows 11 or Windows 10, Microsoft recommends researching hard drive manufacturers and models to determine whether any of their encrypted hard drives meet the security and budget requirements.
For more information about encrypted hard drives, see [Encrypted hard drive](../encrypted-hard-drive.md).
## Preboot information protection
An effective implementation of information protection, like most security controls, considers usability and security. Users typically prefer a simple security experience. In fact, the more transparent a security solution becomes, the more likely users are to conform to it.
It's crucial that organizations protect information on their PCs regardless of the state of the computer or the intent of users. This protection shouldn't be cumbersome to users. One undesirable and previously commonplace situation is when the user is prompted for input during preboot, and then again during Windows sign-in. Challenging users for input more than once should be avoided.
Windows 11 and Windows 10 can enable a true SSO experience from the preboot environment on modern devices and in some cases even on older devices when robust information protection configurations are in place. The TPM in isolation is able to securely protect the BitLocker encryption key while it is at rest, and it can securely unlock the operating system drive. When the key is in use and thus in memory, a combination of hardware and Windows capabilities can secure the key and prevent unauthorized access through cold-boot attacks. Although other countermeasures like PIN-based unlock are available, they aren't as user-friendly; depending on the devices' configuration they may not offer additional security when it comes to key protection. For more information, see [BitLocker Countermeasures](bitlocker-countermeasures.md).
## Manage passwords and PINs
When BitLocker is enabled on a system drive and the PC has a TPM, users can be required to type a PIN before BitLocker will unlock the drive. Such a PIN requirement can prevent an attacker who has physical access to a PC from even getting to the Windows sign-in, which makes it almost impossible for the attacker to access or modify user data and system files.
Requiring a PIN at startup is a useful security feature because it acts as a second authentication factor. However, this configuration comes with some costs. One of the most significant costs is the need to change the PIN regularly. In enterprises that used BitLocker with Windows 7 and the Windows Vista operating system, users had to contact systems administrators to update their BitLocker PIN or password. This requirement not only increased management costs but made users less willing to change their BitLocker PIN or password regularly.
Windows 11 and Windows 10 users can update their BitLocker PINs and passwords themselves, without administrator credentials. Not only will this feature reduce support costs, but it could improve security, too, because it encourages users to change their PINs and passwords more often. In addition, Modern Standby devices don't require a PIN for startup: They're designed to start infrequently and have other mitigations in place that further reduce the attack surface of the system.
For more information about how startup security works and the countermeasures that Windows 11 and Windows 10 provide, see [Protect BitLocker from pre-boot attacks](./bitlocker-countermeasures.md).
## Configure Network Unlock
Some organizations have location specific data security requirements. Location specific data security requirements are most common in environments where high-value data is stored on PCs. The network environment may provide crucial data protection and enforce mandatory authentication. Therefore, policy states that those PCs shouldn't leave the building or be disconnected from the corporate network. Safeguards like physical security locks and geofencing may help enforce this policy as reactive controls. Beyond these safeguards, a proactive security control that grants data access only when the PC is connected to the corporate network is necessary.
Network Unlock enables BitLocker-protected PCs to start automatically when connected to a wired corporate network on which Windows Deployment Services runs. Anytime the PC isn't connected to the corporate network, a user must type a PIN to unlock the drive (if PIN-based unlock is enabled).
Network Unlock requires the following infrastructure:
- Client PCs that have Unified Extensible Firmware Interface (UEFI) firmware version 2.3.1 or later, which supports Dynamic Host Configuration Protocol (DHCP)
- A server running at least Windows Server 2012 with the Windows deployment services (WDS) role
- A server with the DHCP server role installed
For more information about how to configure Network unlock feature, see [BitLocker: How to enable Network Unlock](bitlocker-how-to-enable-network-unlock.md).
## Microsoft BitLocker administration and monitoring
Part of the Microsoft Desktop Optimization Pack, Microsoft BitLocker Administration and Monitoring (MBAM) makes it easier to manage and support BitLocker and BitLocker To Go. MBAM 2.5 with Service Pack 1, the latest version, has the following key features:
- Enables administrators to automate the process of encrypting volumes on client computers across the enterprise.
- Enables security officers to quickly determine the compliance state of individual computers or even of the enterprise itself.
- Provides centralized reporting and hardware management with Microsoft Configuration Manager.
- Reduces the workload on the help desk to assist end users with BitLocker recovery requests.
- Enables end users to recover encrypted devices independently by using the Self-Service Portal.
- Enables security officers to easily audit access to recovery key information.
- Empowers Windows Enterprise users to continue working anywhere with the assurance that their corporate data is protected.
- Enforces the BitLocker encryption policy options that are set for the enterprise.
- Integrates with existing management tools, such as Microsoft Configuration Manager.
- Offers an IT-customizable recovery user experience.
- Supports Windows 11 and Windows 10.
> [!IMPORTANT]
> Enterprises could use MBAM to manage client computers with BitLocker that are domain-joined on-premises until mainstream support ended in July 2019, or they could receive extended support until April 2026.
Going forward, the functionality of MBAM will be incorporated into Configuration Manager. For more information, see [Plan for BitLocker management](/mem/configmgr/protect/plan-design/bitlocker-management).
Enterprises not using Configuration Manager can use the built-in features of Azure AD and Microsoft Intune for administration and monitoring. For more information, see [Monitor device encryption with Intune](/mem/intune/protect/encryption-monitor).

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### YamlMime:FAQ
metadata:
title: BitLocker FAQ (Windows 10)
description: Find the answers you need by exploring this brief hub page listing FAQ pages for various aspects of BitLocker.
author: paolomatarazzo
ms.author: paoloma
ms.collection:
- highpri
- tier1
ms.topic: faq
ms.date: 11/08/2022
appliesto:
- ✅ <a href=https://learn.microsoft.com/windows/release-health/supported-versions-windows-client target=_blank>Windows 11</a>
- ✅ <a href=https://learn.microsoft.com/windows/release-health/supported-versions-windows-client target=_blank>Windows 10</a>
- ✅ <a href=https://learn.microsoft.com/windows/release-health/windows-server-release-info target=_blank>Windows Server 2022</a>
- ✅ <a href=https://learn.microsoft.com/windows/release-health/windows-server-release-info target=_blank>Windows Server 2019</a>
- ✅ <a href=https://learn.microsoft.com/windows/release-health/windows-server-release-info target=_blank>Windows Server 2016</a>
title: BitLocker frequently asked questions (FAQ) resources
summary: This article links to frequently asked questions about BitLocker. BitLocker is a data protection feature that encrypts drives on computers to help prevent data theft or exposure. BitLocker-protected computers can also delete data more securely when they're decommissioned because it's much more difficult to recover deleted data from an encrypted drive than from a non-encrypted drive.
- [Overview and requirements](bitlocker-overview-and-requirements-faq.yml)
- [Upgrading](bitlocker-upgrading-faq.yml)
- [Deployment and administration](bitlocker-deployment-and-administration-faq.yml)
- [Key management](bitlocker-key-management-faq.yml)
- [BitLocker To Go](bitlocker-to-go-faq.yml)
- [Active Directory Domain Services (AD DS)](bitlocker-and-adds-faq.yml)
- [Security](bitlocker-security-faq.yml)
- [BitLocker Network Unlock](bitlocker-network-unlock-faq.yml)
- [Using BitLocker with other programs and general questions](bitlocker-using-with-other-programs-faq.yml)
sections:
- name: Ignored
questions:
- question: |
More information
answer: |
- [Prepare your organization for BitLocker: Planning and Policies](prepare-your-organization-for-bitlocker-planning-and-policies.md)
- [BitLocker Group Policy settings](bitlocker-group-policy-settings.md)
- [BCD settings and BitLocker](bcd-settings-and-bitlocker.md)
- [BitLocker: How to enable Network Unlock](bitlocker-how-to-enable-network-unlock.md)
- [BitLocker: How to deploy on Windows Server 2012](bitlocker-how-to-deploy-on-windows-server.md)
- [BitLocker: Use BitLocker Drive Encryption Tools to manage BitLocker](bitlocker-use-bitlocker-drive-encryption-tools-to-manage-bitlocker.md)
- [BitLocker: Use BitLocker Recovery Password Viewer](bitlocker-use-bitlocker-recovery-password-viewer.md)
- [BitLocker Cmdlets in Windows PowerShell](/powershell/module/bitlocker/index?view=win10-ps&preserve-view=true)

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---
title: BitLocker How to deploy on Windows Server 2012 and later
description: This article for the IT professional explains how to deploy BitLocker and Windows Server 2012 and later
ms.topic: conceptual
ms.date: 11/08/2022
---
# BitLocker: How to deploy on Windows Server 2012 and later
**Applies to:**
- Windows Server 2012
- Windows Server 2012 R2
- Windows Server 2016 and above
This article explains how to deploy BitLocker on Windows Server 2012 and later versions. For all Windows Server editions, BitLocker can be installed using Server Manager or Windows PowerShell cmdlets. BitLocker requires administrator privileges on the server on which it's to be installed.
## Installing BitLocker
### To install BitLocker using server manager
1. Open server manager by selecting the server manager icon or running servermanager.exe.
2. Select **Manage** from the **Server Manager Navigation** bar and select **Add Roles and Features** to start the **Add Roles and Features Wizard.**
3. With the **Add Roles and Features** wizard open, select **Next** at the **Before you begin** pane (if shown).
4. Select **Role-based or feature-based installation** on the **Installation type** pane of the **Add Roles and Features** wizard and select **Next** to continue.
5. Select the **Select a server from the server pool** option in the **Server Selection** pane and confirm the server on which the BitLocker feature is to be installed.
6. Select **Next** on the **Server Roles** pane of the **Add Roles and Features** wizard to proceed to the **Features** pane.
> [!NOTE]
> Server roles and features are installed by using the same wizard in Server Manager.
7. Select the check box next to **BitLocker Drive Encryption** within the **Features** pane of the **Add Roles and Features** wizard. The wizard shows the extra management features available for BitLocker. If the extra management features are not needed and/or don't need to be installed, deselect the **Include management tools**.
> [!NOTE]
> The **Enhanced Storage** feature is a required feature for enabling BitLocker. This feature enables support for encrypted hard drives on capable systems.
8. Select **Add Features**. Once optional features selection is complete, select **Next** to proceed in the wizard.
9. Select **Install** on the **Confirmation** pane of the **Add Roles and Features** wizard to begin BitLocker feature installation. The BitLocker feature requires a restart for its installation to be complete. Selecting the **Restart the destination server automatically if required** option in the **Confirmation** pane forces a restart of the computer after installation is complete.
10. If the **Restart the destination server automatically if required** check box isn't selected, the **Results** pane of the **Add Roles and Features** wizard displays the success or failure of the BitLocker feature installation. If necessary, a notification of other action necessary to complete the feature installation, such as the restart of the computer, will be displayed in the results text.
### To install BitLocker using Windows PowerShell
Windows PowerShell offers administrators another option for BitLocker feature installation. Windows PowerShell installs features using the `servermanager` or `dism.exe` module. However, the `servermanager` and `dism.exe` modules don't always share feature name parity. Because of this mismatch of feature name parity, it's advisable to confirm the feature or role name prior to installation.
> [!NOTE]
> The server must be restarted to complete the installation of BitLocker.
### Using the servermanager module to install BitLocker
The `servermanager` Windows PowerShell module can use either the `Install-WindowsFeature` or `Add-WindowsFeature` to install the BitLocker feature. The `Add-WindowsFeature` cmdlet is merely a stub to the `Install-WindowsFeature`. This example uses the `Install-WindowsFeature` cmdlet. The feature name for BitLocker in the `servermanager` module is `BitLocker`.
By default, installation of features in Windows PowerShell doesn't include optional sub-features or management tools as part of the installation process. What is installed as part of the installation process can be seen using the `-WhatIf` option in Windows PowerShell.
```powershell
Install-WindowsFeature BitLocker -WhatIf
```
The results of this command show that only the BitLocker Drive Encryption feature is installed using this command.
To see what would be installed with the BitLocker feature, including all available management tools and sub-features, use the following command:
```powershell
Install-WindowsFeature BitLocker -IncludeAllSubFeature -IncludeManagementTools -WhatIf | fl
```
The result of this command displays the following list of all the administration tools for BitLocker, which would be installed along with the feature, including tools for use with Active Directory Domain Services (AD DS) and Active Directory Lightweight Directory Services (AD LDS).
- BitLocker Drive Encryption
- BitLocker Drive Encryption Tools
- BitLocker Drive Encryption Administration Utilities
- BitLocker Recovery Password Viewer
- AD DS Snap-Ins and Command-Line Tools
- AD DS Tools
- AD DS and AD LDS Tools
The command to complete a full installation of the BitLocker feature with all available sub-features and then to reboot the server at completion is:
```powershell
Install-WindowsFeature BitLocker -IncludeAllSubFeature -IncludeManagementTools -Restart
```
> [!IMPORTANT]
> Installing the BitLocker feature using Windows PowerShell does not install the Enhanced Storage feature. Administrators wishing to support Encrypted Hard Drives in their environment will need to install the Enhanced Storage feature separately.
### Using the dism module to install BitLocker
The `dism.exe` Windows PowerShell module uses the `Enable-WindowsOptionalFeature` cmdlet to install features. The BitLocker feature name for BitLocker is `BitLocker`. The `dism.exe` module doesn't support wildcards when searching for feature names. To list feature names for the `dism.exe` module, use the `Get-WindowsOptionalFeatures` cmdlet. The following command will list all of the optional features in an online (running) operating system.
```powershell
Get-WindowsOptionalFeature -Online | ft
```
From this output, it can be seen that there are three BitLocker-related optional feature names: **BitLocker**, **BitLocker-Utilities** and **BitLocker-NetworkUnlock**. To install the BitLocker feature, the **BitLocker** and **BitLocker-Utilities** features are the only required items.
To install BitLocker using the `dism.exe` module, use the following command:
```powershell
Enable-WindowsOptionalFeature -Online -FeatureName BitLocker -All
```
This command prompts the user for a reboot. The Enable-WindowsOptionalFeature cmdlet doesn't offer support for forcing a reboot of the computer. This command doesn't include installation of the management tools for BitLocker. For a complete installation of BitLocker and all available management tools, use the following command:
```powershell
Enable-WindowsOptionalFeature -Online -FeatureName BitLocker, BitLocker-Utilities -All
```
## Related articles
- [BitLocker overview](bitlocker-overview.md)
- [BitLocker frequently asked questions (FAQ)](bitlocker-frequently-asked-questions.yml)
- [Prepare your organization for BitLocker: Planning and policies](prepare-your-organization-for-bitlocker-planning-and-policies.md)
- [BitLocker: How to enable Network Unlock](bitlocker-how-to-enable-network-unlock.md)

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---
title: BitLocker - How to enable Network Unlock
description: This article for the IT professional describes how BitLocker Network Unlock works and how to configure it.
ms.topic: conceptual
ms.date: 11/08/2022
---
# BitLocker: How to enable Network Unlock
**Applies to:**
- Windows 10
- Windows 11
- Windows Server 2016 and above
This article describes how BitLocker Network Unlock works and how to configure it.
Network Unlock is a BitLocker protector option for operating system volumes. Network Unlock enables easier management for BitLocker-enabled desktops and servers in a domain environment by providing automatic unlock of operating system volumes at system reboot when connected to a wired corporate network. This feature requires the client hardware to have a DHCP driver implemented in its UEFI firmware. Without Network Unlock, operating system volumes protected by TPM+PIN protectors require a PIN to be entered when a computer reboots or resumes from hibernation (for example, by Wake on LAN). Requiring a PIN after a reboot can make it difficult to enterprises to roll out software patches to unattended desktops and remotely administered servers.
Network Unlock allows BitLocker-enabled systems that have a TPM+PIN and that meet the hardware requirements to boot into Windows without user intervention. Network Unlock works in a similar fashion to the TPM+StartupKey at boot. Rather than needing to read the StartupKey from USB media, however, the Network Unlock feature needs the key to be composed from a key stored in the TPM and an encrypted network key that is sent to the server, decrypted and returned to the client in a secure session.
## Network Unlock core requirements
Network Unlock must meet mandatory hardware and software requirements before the feature can automatically unlock domain-joined systems. These requirements include:
- Currently supported Windows operating system
- Any supported operating system with UEFI DHCP drivers that can serve as Network Unlock clients
- Network Unlock clients with a TPM chip and at least one TPM protector
- A server running the Windows Deployment Services (WDS) role on any supported server operating system
- BitLocker Network Unlock optional feature installed on any supported server operating system
- A DHCP server, separate from the WDS server
- Properly configured public/private key pairing
- Network Unlock group policy settings configured
- Network stack enabled in the UEFI firmware of client devices
> [!NOTE]
> To properly support DHCP within UEFI, the UEFI-based system should be in native mode and shouldn't have a compatibility support module (CSM) enabled.
For Network Unlock to work reliably on computers, the first network adapter on the computer, usually the onboard adapter, must be configured to support DHCP. This first network adapter must be used for Network Unlock. This configuration is especially worth noting when the device has multiple adapters, and some adapters are configured without DHCP, such as for use with a lights-out management protocol. This configuration is necessary because Network Unlock stops enumerating adapters when it reaches one with a DHCP port failure for any reason. Thus, if the first enumerated adapter doesn't support DHCP, isn't plugged into the network, or fails to report availability of the DHCP port for any reason, then Network Unlock fails.
The Network Unlock server component is installed on supported versions of Windows Server 2012 and later as a Windows feature that uses Server Manager or Windows PowerShell cmdlets. The feature name is BitLocker Network Unlock in Server Manager and BitLocker-NetworkUnlock in Windows PowerShell. This feature is a core requirement.
Network Unlock requires Windows Deployment Services (WDS) in the environment where the feature will be utilized. Configuration of the WDS installation isn't required. However, the WDS service must be running on the server.
The network key is stored on the system drive along with an AES 256 session key and encrypted with the 2048-bit RSA public key of the Unlock server certificate. The network key is decrypted with the help of a provider on a supported version of Windows Server running WDS, and returned encrypted with its corresponding session key.
## Network Unlock sequence
The unlock sequence starts on the client side when the Windows boot manager detects the existence of Network Unlock protector. It uses the DHCP driver in UEFI to obtain an IP address for IPv4 and then broadcasts a vendor-specific DHCP request that contains the network key and a session key for the reply, all encrypted by the server's Network Unlock certificate, as described above. The Network Unlock provider on the supported WDS server recognizes the vendor-specific request, decrypts it with the RSA private key, and returns the network key encrypted with the session key via its own vendor-specific DHCP reply.
On the server side, the WDS server role has an optional plugin component, like a PXE provider, which is what handles the incoming Network Unlock requests. The provider can also be configured with subnet restrictions, which would require that the IP address provided by the client in the Network Unlock request belong to a permitted subnet to release the network key to the client. In instances where the Network Unlock provider is unavailable, BitLocker fails over to the next available protector to unlock the drive. In a typical configuration, the standard TPM+PIN unlock screen is presented to unlock the drive.
The server side configuration to enable Network Unlock also requires provisioning a 2048-bit RSA public/private key pair in the form of an X.509 certificate, and distributing the public key certificate to the clients. This certificate must be managed and deployed through the Group Policy editor directly on a domain controller with at least a Domain Functional Level of Windows Server 2012. This certificate is the public key that encrypts the intermediate network key (which is one of the two secrets required to unlock the drive; the other secret is stored in the TPM).
Manage and deploy this certificate through the Group Policy editor directly on a domain controller that has a domain functional level of at least Windows Server 2012. This certificate is the public key that encrypts the intermediate network key. The intermediate network key is one of the two secrets that are required to unlock the drive; the other secret is stored in the TPM.
![Diagram showing the BitLocker Network Unlock sequence.](images/bitlockernetworkunlocksequence.png)
The Network Unlock process follows these phases:
1. The Windows boot manager detects a Network Unlock protector in the BitLocker configuration.
2. The client computer uses its DHCP driver in the UEFI to get a valid IPv4 IP address.
3. The client computer broadcasts a vendor-specific DHCP request that contains:
1. A network key (a 256-bit intermediate key) that is encrypted by using the 2048-bit RSA Public Key of the Network Unlock certificate from the WDS server.
2. An AES-256 session key for the reply.
4. The Network Unlock provider on the WDS server recognizes the vendor-specific request.
5. The provider decrypts the request by using the WDS server's BitLocker Network Unlock certificate RSA private key.
6. The WDS provider returns the network key encrypted with the session key by using its own vendor-specific DHCP reply to the client computer. This key is an intermediate key.
7. The returned intermediate key is combined with another local 256-bit intermediate key. This key can be decrypted only by the TPM.
8. This combined key is used to create an AES-256 key that unlocks the volume.
9. Windows continues the boot sequence.
## Configure Network Unlock
The following steps allow an administrator to configure Network Unlock in a domain where the Domain Functional Level is at least Windows Server 2012.
### Install the WDS server role
The BitLocker Network Unlock feature installs the WDS role if it isn't already installed. WDS can be installed separately before BitLocker Network Unlock is installed by using **Server Manager** or **Windows PowerShell**. To install the role using Server Manager, select the **Windows Deployment Services** role in **Server Manager**.
To install the role by using Windows PowerShell, use the following command:
```powershell
Install-WindowsFeature WDS-Deployment
```
The WDS server must be configured so that it can communicate with DHCP (and optionally AD DS) and the client computer. The WDS server can be configured using the WDS management tool, `wdsmgmt.msc`, which starts the Windows Deployment Services Configuration wizard.
### Confirm the WDS service is running
To confirm that the WDS service is running, use the Services Management Console or Windows PowerShell. To confirm that the service is running in Services Management Console, open the console using `services.msc` and check the status of the Windows Deployment Services service.
To confirm that the service is running using Windows PowerShell, use the following command:
```powershell
Get-Service WDSServer
```
### Install the Network Unlock feature
To install the Network Unlock feature, use Server Manager or Windows PowerShell. To install the feature using Server Manager, select the **BitLocker Network Unlock** feature in the Server Manager console.
To install the feature by using Windows PowerShell, use the following command:
```powershell
Install-WindowsFeature BitLocker-NetworkUnlock
```
### Create the certificate template for Network Unlock
A properly configured Active Directory Services Certification Authority can use this certificate template to create and issue Network Unlock certificates.
1. Open the Certificates Template snap-in (`certtmpl.msc`).
2. Locate the User template, right-click the template name and select **Duplicate Template**.
3. On the **Compatibility** tab, change the **Certification Authority** and **Certificate recipient** fields to Windows Server 2012 and Windows 8, respectively. Ensure that the **Show resulting changes** dialog box is selected.
4. Select the **General** tab of the template. The **Template display name** and **Template name** should clearly identify that the template will be used for Network Unlock. Clear the check box for the **Publish certificate in Active Directory** option.
5. Select the **Request Handling** tab. Select **Encryption** from the **Purpose** drop-down menu. Ensure that the **Allow private key to be exported** option is selected.
6. Select the **Cryptography** tab. Set the **Minimum key size** to 2048. Any Microsoft cryptographic provider that supports RSA can be used for this template, but for simplicity and forward compatibility, it is recommended to use **Microsoft Software Key Storage Provider**.
7. Select the **Requests must use one of the following providers** option and clear all options except for the cryptography provider selected, such as **Microsoft Software Key Storage Provider**.
8. Select the **Subject Name** tab. Select **Supply in the request**. Select **OK** if the certificate templates pop-up dialog appears.
9. Select the **Issuance Requirements** tab. Select both **CA certificate manager approval** and **Valid existing certificate** options.
10. Select the **Extensions** tab. Select **Application Policies** and choose **Edit…**.
11. In the **Edit Application Policies Extension** options dialog box, select **Client Authentication**, **Encrypting File System**, **and Secure Email** and choose **Remove**.
12. On the **Edit Application Policies Extension** dialog box, select **Add**.
13. On the **Add Application Policy** dialog box, select **New**. In the **New Application Policy** dialog box, enter the following information in the space provided and then select **OK** to create the BitLocker Network Unlock application policy:
- *Name:* **BitLocker Network Unlock**
- *Object Identifier:* **1.3.6.1.4.1.311.67.1.1**
14. Select the newly created **BitLocker Network Unlock** application policy and select **OK**.
15. With the **Extensions** tab still open, select the **Edit Key Usage Extension** dialog. Select the **Allow key exchange only with key encryption (key encipherment)** option. Select the **Make this extension critical** option.
16. Select the **Security** tab. Confirm that the **Domain Admins** group has been granted **Enroll** permission.
17. Select **OK** to complete configuration of the template.
To add the Network Unlock template to the certificate authority, open the certificate authority snap-in (`certsrv.msc`). Right-click **Certificate Templates**, and then choose **New, Certificate Template to issue**. Select the previously created BitLocker Network Unlock certificate.
After the Network Unlock template is added to the certificate authority, this certificate can be used to configure BitLocker Network Unlock.
### Create the Network Unlock certificate
Network Unlock can use imported certificates from an existing public key infrastructure (PKI). Or it can use a self-signed certificate.
To enroll a certificate from an existing certificate authority:
1. On the WDS server, open Certificate Manager by using `certmgr.msc`.
2. Under **Certificates - Current User**, right-click **Personal**.
3. Select **All Tasks** > **Request New Certificate**.
4. When the Certificate Enrollment wizard opens, select **Next**.
5. Select **Active Directory Enrollment Policy**.
6. Choose the certificate template that was created for Network Unlock on the domain controller. Then select **Enroll**.
7. When prompted for more information, select **Subject Name** and provide a friendly name value. The friendly name should include information for the domain or organizational unit for the certificate. For example:
*BitLocker Network Unlock Certificate for Contoso domain*
8. Create the certificate. Ensure the certificate appears in the **Personal** folder.
9. Export the public key certificate for Network Unlock:
1. Create a `.cer` file by right-clicking the previously created certificate, selecting **All Tasks**, and then selecting **Export**.
2. Select **No, do not export the private key**.
3. Select **DER encoded binary X.509** and complete exporting the certificate to a file.
4. Give the file a name such as BitLocker-NetworkUnlock.cer.
10. Export the public key with a private key for Network Unlock.
1. Create a `.pfx` file by right-clicking the previously created certificate, selecting **All Tasks**, and then selecting **Export**.
2. Select **Yes, export the private key**.
3. Complete the steps to create the `.pfx` file.
To create a self-signed certificate, either use the `New-SelfSignedCertificate` cmdlet in Windows PowerShell or use `certreq.exe`. For example:
**Windows PowerShell:**
```powershell
New-SelfSignedCertificate -CertStoreLocation Cert:\LocalMachine\My -Subject "CN=BitLocker Network Unlock certificate" -Provider "Microsoft Software Key Storage Provider" -KeyUsage KeyEncipherment -KeyUsageProperty Decrypt,Sign -KeyLength 2048 -HashAlgorithm sha512 -TextExtension @("1.3.6.1.4.1.311.21.10={text}OID=1.3.6.1.4.1.311.67.1.1","2.5.29.37={text}1.3.6.1.4.1.311.67.1.1")
```
**certreq.exe:**
1. Create a text file with an `.inf` extension, for example:
```cmd
notepad.exe BitLocker-NetworkUnlock.inf
```
2. Add the following contents to the previously created file:
```ini
[NewRequest]
Subject="CN=BitLocker Network Unlock certificate"
ProviderType=0
MachineKeySet=True
Exportable=true
RequestType=Cert
KeyUsage="CERT_KEY_ENCIPHERMENT_KEY_USAGE"
KeyUsageProperty="NCRYPT_ALLOW_DECRYPT_FLAG | NCRYPT_ALLOW_SIGNING_FLAG"
KeyLength=2048
SMIME=FALSE
HashAlgorithm=sha512
[Extensions]
1.3.6.1.4.1.311.21.10 = "{text}"
_continue_ = "OID=1.3.6.1.4.1.311.67.1.1"
2.5.29.37 = "{text}"
_continue_ = "1.3.6.1.4.1.311.67.1.1"
```
3. Open an elevated command prompt and use the `certreq.exe` tool to create a new certificate. Use the following command, specifying the full path to the file that was created previously along with the file name:
```cmd
certreq.exe -new BitLocker-NetworkUnlock.inf BitLocker-NetworkUnlock.cer
```
4. Verify that certificate was properly created by the previous command by confirming that the `.cer` file exists.
5. Launch the **Certificates - Local Computer** console by running `certlm.msc`.
6. Create a `.pfx` file by following the below steps the **Certificates - Local Computer** console:
1. Navigate to **Certificates - Local Computer** > **Personal** > **Certificates**
2. Right-click the previously imported certificate, select **All Tasks**, and then select **Export**
3. Follow through the wizard to create the `.pfx` file.
### Deploy the private key and certificate to the WDS server
After creating the certificate and key, deploy them to the infrastructure to properly unlock systems. To deploy the certificates:
1. On the WDS server, launch the **Certificates - Local Computer** console by running `certlm.msc`.
2. Right-click **BitLocker Drive Encryption Network Unlock** item under **Certificates (Local Computer)**, select **All Tasks**, and then select **Import**.
3. In the **File to Import** dialog, choose the `.pfx` file created previously.
4. Enter the password used to create the `.pfx` and complete the wizard.
### Configure group policy settings for Network Unlock
With certificate and key deployed to the WDS server for Network Unlock, the final step is to use group policy settings to deploy the public key certificate to the desired computers that will use the Network Unlock key to unlock. Group policy settings for BitLocker can be found under **Computer Configuration** > **Administrative Templates** > **Windows Components** > **BitLocker Drive Encryption** using the Local Group Policy Editor or the Microsoft Management Console.
The following steps describe how to enable the group policy setting that is a requirement for configuring Network Unlock.
1. Open Group Policy Management Console (`gpmc.msc`).
2. Enable the policy **Require additional authentication at startup**, and then select **Require startup PIN with TPM** or **Allow startup PIN with TPM**.
3. Turn on BitLocker with TPM+PIN protectors on all domain-joined computers.
The following steps describe how to deploy the required group policy setting:
> [!NOTE]
> The group policy settings **Allow Network Unlock at startup** and **Add Network Unlock Certificate** were introduced in Windows Server 2012.
1. Copy the `.cer` file that was created for Network Unlock to the domain controller.
2. On the domain controller, open Group Policy Management Console (`gpmc.msc`).
3. Create a new Group Policy Object or modify an existing object to enable the **Allow Network Unlock at startup** setting.
4. Deploy the public certificate to clients:
1. Within group policy management console, navigate to the following location:
**Computer Configuration** > **Policies** > **Windows Settings** > **Security Settings** > **Public Key Policies** > **BitLocker Drive Encryption Network Unlock Certificate**.
2. Right-click the folder and select **Add Network Unlock Certificate**.
3. Follow the wizard steps and import the `.cer` file that was copied earlier.
> [!NOTE]
> Only one Network Unlock certificate can be available at a time. If a new certificate is needed, delete the current certificate before deploying a new one. The Network Unlock certificate is located under the **`HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\SystemCertificates\FVE_NKP`** registry key on the client computer.
5. Reboot the clients after the Group Policy is deployed.
> [!NOTE]
> The **Network (Certificate Based)** protector will be added only after a reboot, with the policy enabled and a valid certificate present in the FVE_NKP store.
### Subnet policy configuration files on the WDS server (optional)
By default, all clients with the correct Network Unlock certificate and valid Network Unlock protectors that have wired access to a Network Unlock-enabled WDS server via DHCP are unlocked by the server. A subnet policy configuration file on the WDS server can be created to limit which are the subnet(s) the Network Unlock clients can use to unlock.
The configuration file, called bde-network-unlock.ini, must be located in the same directory as the Network Unlock provider DLL (`%windir%\System32\Nkpprov.dll`) and it applies to both IPv6 and IPv4 DHCP implementations. If the subnet configuration policy becomes corrupted, the provider fails and stops responding to requests.
The subnet policy configuration file must use a **\[SUBNETS\]** section to identify the specific subnets. The named subnets may then be used to specify restrictions in certificate subsections. Subnets are defined as simple name-value pairs, in the common INI format, where each subnet has its own line, with the name on the left of the equal-sign, and the subnet identified on the right of the equal-sign as a Classless Inter-Domain Routing (CIDR) address or range. The key word **ENABLED** is disallowed for subnet names.
```ini
[SUBNETS]
SUBNET1=10.185.250.0/24 ; a comment about this subrange could be here, after the semicolon
SUBNET2=10.185.252.200/28
SUBNET3= 2001:4898:a:2::/64 ; an IPv6 subnet
SUBNET4=2001:4898:a:3::/64; in production, the admin would likely give more useful names, like BUILDING9-EXCEPT-RECEP.
```
Following the **\[SUBNETS\]** section, there can be sections for each Network Unlock certificate, identified by the certificate thumbprint formatted without any spaces, which define the subnets clients that can be unlocked from that certificate.
> [!NOTE]
> When specifying the certificate thumbprint, do not include any spaces. If spaces are included in the thumbprint, the subnet configuration fails because the thumbprint will not be recognized as valid.
Subnet restrictions are defined within each certificate section by denoting the allowed list of permitted subnets. If any subnets are listed in a certificate section, then only those subnets are permitted for that certificate. If no subnet is listed in a certificate section, then all subnets are permitted for that certificate. If a certificate doesn't have a section in the subnet policy configuration file, then no subnet restrictions are applied for unlocking with that certificate. For restrictions to apply to every certificate, there must be a certificate section for every Network Unlock certificate on the server, and an explicit allowed list set for each certificate section.
Subnet lists are created by putting the name of a subnet from the **\[SUBNETS\]** section on its own line below the certificate section header. Then, the server will only unlock clients with this certificate on the subnet(s) specified as in the list. For troubleshooting, a subnet can be quickly excluded without deleting it from the section by commenting it out with a prepended semi-colon.
```ini
[2158a767e1c14e88e27a4c0aee111d2de2eafe60]
;Comments could be added here to indicate when the cert was issued, which Group Policy should get it, and so on.
;This list shows this cert is allowed to unlock clients only on the SUBNET1 and SUBNET3 subnets. In this example, SUBNET2 is commented out.
SUBNET1
;SUBNET2
SUBNET3
```
To disallow the use of a certificate altogether, add a `DISABLED` line to its subnet list.
## Turn off Network Unlock
To turn off the unlock server, the PXE provider can be unregistered from the WDS server or uninstalled altogether. However, to stop clients from creating Network Unlock protectors, the **Allow Network Unlock at startup** group policy setting should be disabled. When this policy setting is updated to **disabled** on client computers, any Network Unlock key protector on the computer is deleted. Alternatively, the BitLocker Network Unlock certificate policy can be deleted on the domain controller to accomplish the same task for an entire domain.
> [!NOTE]
> Removing the FVE_NKP certificate store that contains the Network Unlock certificate and key on the WDS server will also effectively disable the server's ability to respond to unlock requests for that certificate. However, this is seen as an error condition and is not a supported or recommended method for turning off the Network Unlock server.
## Update Network Unlock certificates
To update the certificates used by Network Unlock, administrators need to import or generate the new certificate for the server, and then update the Network Unlock certificate group policy setting on the domain controller.
> [!NOTE]
> Servers that don't receive the Group Policy Object (GPO) will require a PIN when they boot. In such cases, find out why the server didn't receive the GPO to update the certificate.
## Troubleshoot Network Unlock
Troubleshooting Network Unlock issues begins by verifying the environment. Many times, a small configuration issue can be the root cause of the failure. Items to verify include:
- Verify that the client hardware is UEFI-based and is on firmware version 2.3.1 and that the UEFI firmware is in native mode without a Compatibility Support Module (CSM) for BIOS mode enabled. Verification can be done by checking that the firmware doesn't have an option enabled such as "Legacy mode" or "Compatibility mode" or that the firmware doesn't appear to be in a BIOS-like mode.
- All required roles and services are installed and started.
- Public and private certificates have been published and are in the proper certificate containers. The presence of the Network Unlock certificate can be verified in the Microsoft Management Console (MMC.exe) on the WDS server with the certificate snap-ins for the local computer enabled. The client certificate can be verified by checking the registry key **`HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\SystemCertificates\FVE_NKP`** on the client computer.
- Group policy for Network Unlock is enabled and linked to the appropriate domains.
- Verify whether group policy is reaching the clients properly. Verification of group policy can be done using the `GPRESULT.exe` or `RSOP.msc` utilities.
- Verify whether the clients were rebooted after applying the policy.
- Verify whether the **Network (Certificate Based)** protector is listed on the client. Verification of the protector can be done using either manage-bde or Windows PowerShell cmdlets. For example, the following command will list the key protectors currently configured on the C: drive of the local computer:
```powershell
manage-bde.exe -protectors -get C:
```
> [!NOTE]
> Use the output of `manage-bde.exe` along with the WDS debug log to determine whether the proper certificate thumbprint is being used for Network Unlock.
Gather the following files to troubleshoot BitLocker Network Unlock.
- The Windows event logs. Specifically, get the BitLocker event logs and the Microsoft-Windows-Deployment-Services-Diagnostics-Debug log.
Debug logging is turned off by default for the WDS server role. To retrieve WDS debug logs, the WDS debug logs first need to be enabled. Use either of the following two methods to turn on WDS debug logging.
- Start an elevated command prompt, and then run the following command:
```cmd
wevtutil.exe sl Microsoft-Windows-Deployment-Services-Diagnostics/Debug /e:true
```
- Open **Event Viewer** on the WDS server:
1. In the left pane, navigate to **Applications and Services Logs** > **Microsoft** > **Windows** > **Deployment-Services-Diagnostics** > **Debug**.
2. In the right pane, select **Enable Log**.
- The DHCP subnet configuration file (if one exists).
- The output of the BitLocker status on the volume. Gather this output into a text file by using `manage-bde.exe -status`. Or in Windows PowerShell, use `Get-BitLockerVolume`.
- The Network Monitor capture on the server that hosts the WDS role, filtered by client IP address.
<!--
REMOVING SECTION DUE TO THE VERSIONS OF WINDOWS THAT THIS SECTION APPLIES TO ARE NO LONGER SUPPORTED.
## Configure Network Unlock Group Policy settings on earlier versions
Network Unlock and the accompanying Group Policy settings were introduced in Windows Server 2012. However Network Unlock and the accompanying Group Policy settings can be deployed using operating systems that run Windows Server 2008 R2 and Windows Server 2008.
The system must meet these requirements:
- The server that hosts WDS must be running a server operating system that's designated in the "Applies to" list at the beginning of this article.
- Client computers must be running a client operating system that's designated in the "Applies to" list at the beginning of this article.
Follow these steps to configure Network Unlock on these older systems.
1. [Install the WDS Server role](#install-the-wds-server-role)
2. [Confirm the WDS Service is running](#confirm-the-wds-service-is-running)
3. [Install the Network Unlock feature](#install-the-network-unlock-feature)
4. [Create the Network Unlock certificate](#create-the-network-unlock-certificate)
5. [Deploy the private key and certificate to the WDS server](#deploy-the-private-key-and-certificate-to-the-wds-server)
6. Configure registry settings for Network Unlock:
Apply the registry settings by running the following `certutil.exe` script (assuming the Network Unlock certificate file is called *BitLocker-NetworkUnlock.cer*) on each computer that runs a client operating system that's designated in the [Applies to](#bitlocker-how-to-enable-network-unlock) list at the beginning of this article.
```cmd
certutil.exe -f -grouppolicy -addstore FVE_NKP BitLocker-NetworkUnlock.cer
reg.exe add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v OSManageNKP /t REG_DWORD /d 1 /f
reg.exe add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v UseAdvancedStartup /t REG_DWORD /d 1 /f
reg.exe add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v UsePIN /t REG_DWORD /d 2 /f
reg.exe add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v UseTPMPIN /t REG_DWORD /d 2 /f
reg.exe add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v UseTPM /t REG_DWORD /d 2 /f
reg.exe add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v UseTPMKey /t REG_DWORD /d 2 /f
reg.exe add "HKLM\SOFTWARE\Policies\Microsoft\FVE" /v UseTPMKeyPIN /t REG_DWORD /d 2 /f
```
7. Set up a TPM protector on the clients.
8. Reboot the clients to add the Network (certificate based) protector.
-->
## Related articles
- [BitLocker overview](bitlocker-overview.md)
- [BitLocker frequently asked questions (FAQ)](bitlocker-frequently-asked-questions.yml)
- [Prepare your organization for BitLocker: Planning and policies](prepare-your-organization-for-bitlocker-planning-and-policies.md)

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### YamlMime:FAQ
metadata:
title: BitLocker Key Management FAQ (Windows 10)
description: Browse frequently asked questions concerning the requirements to use, upgrade, deploy and administer, and key management policies for BitLocker.
ms.prod: windows-client
ms.technology: itpro-security
author: frankroj
ms.author: frankroj
manager: aaroncz
ms.topic: faq
ms.date: 11/08/2022
title: BitLocker Key Management FAQ
summary: |
sections:
- name: Ignored
questions:
- question: How can I authenticate or unlock my removable data drive?
answer: |
Removable data drives can be unlocked using a password or a smart card. An SID protector can also be configured to unlock a drive by using user domain credentials. After encryption has started, the drive can also be automatically unlocked on a specific computer for a specific user account. System administrators can configure which options are available for users including password complexity and minimum length requirements. To unlock by using a SID protector, use `manage-bde.exe`:
```cmd
Manage-bde.exe -protectors -add e: -sid <i>domain\username</i></code>
```
- question: What is the difference between a recovery password, recovery key, PIN, enhanced PIN, and startup key?
answer: |
For tables that list and describe elements such as a recovery password, recovery key, and PIN, see [BitLocker key protectors](prepare-your-organization-for-bitlocker-planning-and-policies.md#bitlocker-key-protectors) and [BitLocker authentication methods](prepare-your-organization-for-bitlocker-planning-and-policies.md#bitlocker-authentication-methods).
- question: How can the recovery password and recovery key be stored?
answer: |
The recovery password and recovery key for an operating system drive or a fixed data drive can be saved to a folder, saved to one or more USB devices, saved to a Microsoft Account, or printed.
For removable data drives, the recovery password and recovery key can be saved to a folder, saved to a Microsoft Account, or printed. By default, a recovery key for a removable drive can't be stored on a removable drive.
A domain administrator can also configure Group Policy to automatically generate recovery passwords and store them in Active Directory Domain Services (AD DS) for any BitLocker-protected drive.
- question: Is it possible to add an additional method of authentication without decrypting the drive if I only have the TPM authentication method enabled?
answer: |
The `Manage-bde.exe` command-line tool can be used to replace TPM-only authentication mode with a multifactor authentication mode. For example, if BitLocker is enabled with TPM authentication only and PIN authentication needs to be added, use the following commands from an elevated command prompt, replacing *4-20 digit numeric PIN* with the desired numeric PIN:
```cmd
manage-bde.exe -protectors -delete %systemdrive% -type tpm
manage-bde.exe -protectors -add %systemdrive% -tpmandpin <4-20 digit numeric PIN>
```
- question: When should an additional method of authentication be considered?
answer: |
New hardware that meets [Windows Hardware Compatibility Program](/windows-hardware/design/compatibility/) requirements make a PIN less critical as a mitigation, and having a TPM-only protector is likely sufficient when combined with policies like device lockout. For example, Surface Pro and Surface Book don't have external DMA ports to attack.
For older hardware, where a PIN may be needed, it's recommended to enable [enhanced PINs](bitlocker-group-policy-settings.md#allow-enhanced-pins-for-startup) that allow non-numeric characters such as letters and punctuation marks, and to set the PIN length based on the risk tolerance and the hardware anti-hammering capabilities available to the TPMs on the computers.
- question: If I lose my recovery information, will the BitLocker-protected data be unrecoverable?
answer: |
BitLocker is designed to make the encrypted drive unrecoverable without the required authentication. When in recovery mode, the user needs the recovery password or recovery key to unlock the encrypted drive.
> [!IMPORTANT]
> Store the recovery information in AD DS, along with in a Microsoft Account, or another safe location.
- question: Can the USB flash drive that is used as the startup key also be used to store the recovery key?
answer: While using a USB flash drive as both the startup key and for storage of the recovery key is technically possible, it isn't a best practice to use one USB flash drive to store both keys. If the USB flash drive that contains the startup key is lost or stolen, the recovery key will also be lost. In addition, inserting this key would cause the computer to automatically boot from the recovery key even if TPM-measured files have changed, which circumvents the TPM's system integrity check.
- question: Can I save the startup key on multiple USB flash drives?
answer: Yes, computer's startup key can be saved on multiple USB flash drives. Right-clicking a BitLocker-protected drive and selecting **Manage BitLocker** will provide the options to save the recovery keys on additional USB flash drives as needed.
- question: Can I save multiple (different) startup keys on the same USB flash drive?
answer: Yes, BitLocker startup keys for different computers can be saved on the same USB flash drive.
- question: Can I generate multiple (different) startup keys for the same computer?
answer: Generating different startup keys for the same computer can be done through scripting. However, for computers that have a TPM, creating different startup keys prevents BitLocker from using the TPM's system integrity check.
- question: Can I generate multiple PIN combinations?
answer: Generating multiple PIN combinations can't be done.
- question: What encryption keys are used in BitLocker? How do they work together?
answer: Raw data is encrypted with the full volume encryption key, which is then encrypted with the volume master key. The volume master key is in turn encrypted by one of several possible methods depending on the authentication (that is, key protectors or TPM) and recovery scenarios.
- question: Where are the encryption keys stored?
answer: |
The full volume encryption key is encrypted by the volume master key and stored in the encrypted drive. The volume master key is encrypted by the appropriate key protector and stored in the encrypted drive. If BitLocker has been suspended, the clear key that is used to encrypt the volume master key is also stored in the encrypted drive, along with the encrypted volume master key.
This storage process ensures that the volume master key is never stored unencrypted and is protected unless BitLocker is disabled. The keys are also saved to two additional locations on the drive for redundancy. The keys can be read and processed by the boot manager.
- question: Why do I have to use the function keys to enter the PIN or the 48-character recovery password?
answer: |
The F1 through F10 keys are universally mapped scan codes available in the pre-boot environment on all computers and in all languages. The numeric keys 0 through 9 aren't usable in the pre-boot environment on all keyboards.
When using an enhanced PIN, users should run the optional system check during the BitLocker setup process to ensure that the PIN can be entered correctly in the pre-boot environment.
- question: How does BitLocker help prevent an attacker from discovering the PIN that unlocks my operating system drive?
answer: |
It's possible that a personal identification number (PIN) can be discovered by an attacker performing a brute force attack. A brute force attack occurs when an attacker uses an automated tool to try different PIN combinations until the correct one is discovered. For BitLocker-protected computers, this type of attack, also known as a dictionary attack, requires that the attacker has physical access to the computer.
The TPM has the built-in ability to detect and react to these types of attacks. Because different manufacturers' TPMs may support different PIN and attack mitigations, contact the TPM's manufacturer to determine how the computer's TPM mitigates PIN brute force attacks.
After the TPM's manufacturer has been determined, contact the manufacturer to gather the TPM's vendor-specific information. Most manufacturers use the PIN authentication failure count to exponentially increase lockout time to the PIN interface. However, each manufacturer has different policies regarding when and how the failure counter is decreased or reset.
- question: How can I determine the manufacturer of my TPM?
answer: The TPM manufacturer can be determined in **Windows Defender Security Center** > **Device Security** > **Security processor details**.
- question: How can I evaluate a TPM's dictionary attack mitigation mechanism?
answer: |
The following questions can assist when asking a TPM manufacturer about the design of a dictionary attack mitigation mechanism:
- How many failed authorization attempts can occur before lockout?
- What is the algorithm for determining the duration of a lockout based on the number of failed attempts and any other relevant parameters?
- What actions can cause the failure count and lockout duration to be decreased or reset?
- question: Can PIN length and complexity be managed with Group Policy?
answer: |
Yes and No. The minimum personal identification number (PIN) length can be configured by using the **Configure minimum PIN length for startup** Group Policy setting and allow the use of alphanumeric PINs by enabling the **Allow enhanced PINs for startup** Group Policy setting. However, PIN complexity can't be required via Group Policy.
For more info, see [BitLocker Group Policy settings](bitlocker-group-policy-settings.md).

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---
title: BitLocker management
description: Refer to relevant documentation, products, and services to learn about managing BitLocker and see recommendations for different computers.
ms.topic: conceptual
ms.date: 11/08/2022
---
# BitLocker management
The ideal solution for BitLocker management is to eliminate the need for IT administrators to set management policies using tools or other mechanisms by having Windows perform tasks that are more practical to automate. This vision leverages modern hardware developments. The growth of TPM 2.0, secure boot, and other hardware improvements, for example, have helped to alleviate the support burden on help desks and a decrease in support-call volumes, yielding improved user satisfaction. Windows continues to be the focus for new features and improvements for built-in encryption management, such as automatically enabling encryption on devices that support Modern Standby beginning with Windows 8.1.
Though much Windows [BitLocker documentation](bitlocker-overview.md) has been published, customers frequently ask for recommendations and pointers to specific, task-oriented documentation that is both easy to digest and focused on how to deploy and manage BitLocker. This article links to relevant documentation, products, and services to help answer this and other related frequently asked questions, and also provides BitLocker recommendations for different types of computers.
[!INCLUDE [bitlocker](../../../../../includes/licensing/bitlocker-management.md)]
## Managing domain-joined computers and moving to cloud
Companies that image their own computers using Configuration Manager can use an existing task sequence to [pre-provision BitLocker](/configmgr/osd/understand/task-sequence-steps#BKMK_PreProvisionBitLocker) encryption while in Windows Preinstallation Environment (WinPE) and can then [enable protection](/configmgr/osd/understand/task-sequence-steps#BKMK_EnableBitLocker). These steps during an operating system deployment can help ensure that computers are encrypted from the start, even before users receive them. As part of the imaging process, a company could also decide to use Configuration Manager to pre-set any desired [BitLocker Group Policy](./bitlocker-group-policy-settings.md).
Enterprises can use [Microsoft BitLocker Administration and Monitoring (MBAM)](/microsoft-desktop-optimization-pack/mbam-v25/) to manage client computers with BitLocker that are domain-joined on-premises until [mainstream support ends in July 2019](/lifecycle/products/?alpha=Microsoft%20BitLocker%20Administration%20and%20Monitoring%202.5%20Service%20Pack%201%2F) or they can receive extended support until April 2026. Thus, over the next few years, a good strategy for enterprises will be to plan and move to cloud-based management for BitLocker. Refer to the [PowerShell examples](#powershell-examples) to see how to store recovery keys in Azure Active Directory (Azure AD).
> [!IMPORTANT]
> Microsoft BitLocker Administration and Monitoring (MBAM) capabilities are offered through Configuration Manager BitLocker Management. See [Plan for BitLocker management](/mem/configmgr/protect/plan-design/bitlocker-management) in the Configuration Manager documentation for additional information.
## Managing devices joined to Azure Active Directory
Devices joined to Azure AD are managed using Mobile Device Management (MDM) policy from an MDM solution such as Microsoft Intune. Prior to Windows 10, version 1809, only local administrators can enable BitLocker via Intune policy. Starting with Windows 10, version 1809, Intune can enable BitLocker for standard users. [BitLocker Device Encryption](bitlocker-device-encryption-overview-windows-10.md#bitlocker-device-encryption) status can be queried from managed machines via the [Policy Configuration Settings Provider (CSP)](/windows/client-management/mdm/policy-configuration-service-provider/), which reports on whether BitLocker Device Encryption is enabled on the device. Compliance with BitLocker Device Encryption policy can be a requirement for [Conditional Access](https://www.microsoft.com/cloud-platform/conditional-access/) to services like Exchange Online and SharePoint Online.
Starting with Windows 10 version 1703, the enablement of BitLocker can be triggered over MDM either by the [Policy CSP](/windows/client-management/mdm/policy-configuration-service-provider/) or the [BitLocker CSP](/windows/client-management/mdm/bitlocker-csp/). The BitLocker CSP adds policy options that go beyond ensuring that encryption has occurred, and is available on computers that run Windows 11, Windows 10, and on Windows phones.
For hardware that is compliant with Modern Standby and HSTI, when using either of these features, [BitLocker Device Encryption](bitlocker-device-encryption-overview-windows-10.md#bitlocker-device-encryption) is automatically turned on whenever the user joins a device to Azure AD. Azure AD provides a portal where recovery keys are also backed up, so users can retrieve their own recovery key for self-service, if necessary. For older devices that aren't yet encrypted, beginning with Windows 10 version 1703, admins can use the [BitLocker CSP](/windows/client-management/mdm/bitlocker-csp/) to trigger encryption and store the recovery key in Azure AD. This process and feature is applicable to Azure Hybrid AD as well.
## Managing workplace-joined PCs and phones
For Windows PCs and Windows Phones that are enrolled using **Connect to work or school account**, BitLocker Device Encryption is managed over MDM, the same as devices joined to Azure AD.
## Managing servers
Servers are often installed, configured, and deployed using PowerShell; therefore, the recommendation is to also use [PowerShell to enable BitLocker on a server](bitlocker-use-bitlocker-drive-encryption-tools-to-manage-bitlocker.md#bitlocker-cmdlets-for-windows-powershell), ideally as part of the initial setup. BitLocker is an Optional Component (OC) in Windows Server; therefore, follow the directions in [BitLocker: How to deploy on Windows Server 2012 and later](bitlocker-how-to-deploy-on-windows-server.md) to add the BitLocker OC.
The Minimal Server Interface is a prerequisite for some of the BitLocker administration tools. On a [Server Core](/windows-server/get-started/getting-started-with-server-core/) installation, the necessary GUI components must be added first. The steps to add shell components to Server Core are described in [Using Features on Demand with Updated Systems and Patched Images](/archive/blogs/server_core/using-features-on-demand-with-updated-systems-and-patched-images) and [How to update local source media to add roles and features](/archive/blogs/joscon/how-to-update-local-source-media-to-add-roles-and-features).
If a server is being installed manually, such as a stand-alone server, then choosing [Server with Desktop Experience](/windows-server/get-started/getting-started-with-server-with-desktop-experience/) is the easiest path because it avoids performing the steps to add a GUI to Server Core.
Additionally, lights-out data centers can take advantage of the enhanced security of a second factor while avoiding the need for user intervention during reboots by optionally using a combination of BitLocker (TPM+PIN) and BitLocker Network Unlock. BitLocker Network Unlock brings together the best of hardware protection, location dependence, and automatic unlock, while in the trusted location. For the configuration steps, see [BitLocker: How to enable Network Unlock](bitlocker-how-to-enable-network-unlock.md).
For more information, see the BitLocker FAQs article and other useful links in [Related Articles](#related-articles).
## PowerShell examples
For Azure AD-joined computers, including virtual machines, the recovery password should be stored in Azure AD.
**Example**: *Use PowerShell to add a recovery password and back it up to Azure AD before enabling BitLocker*
```powershell
Add-BitLockerKeyProtector -MountPoint "C:" -RecoveryPasswordProtector
$BLV = Get-BitLockerVolume -MountPoint "C:"
BackupToAAD-BitLockerKeyProtector -MountPoint "C:" -KeyProtectorId $BLV.KeyProtector[0].KeyProtectorId
```
For domain-joined computers, including servers, the recovery password should be stored in Active Directory Domain Services (AD DS).
**Example**: *Use PowerShell to add a recovery password and back it up to AD DS before enabling BitLocker*
```powershell
Add-BitLockerKeyProtector -MountPoint "C:" -RecoveryPasswordProtector
$BLV = Get-BitLockerVolume -MountPoint "C:"
Backup-BitLockerKeyProtector -MountPoint "C:" -KeyProtectorId $BLV.KeyProtector[0].KeyProtectorId
```
PowerShell can then be used to enable BitLocker:
**Example**: *Use PowerShell to enable BitLocker with a TPM protector*
```powershell
Enable-BitLocker -MountPoint "D:" -EncryptionMethod XtsAes256 -UsedSpaceOnly -TpmProtector
```
**Example**: *Use PowerShell to enable BitLocker with a TPM+PIN protector, in this case with a PIN set to 123456*
```powershell
$SecureString = ConvertTo-SecureString "123456" -AsPlainText -Force
Enable-BitLocker -MountPoint "C:" -EncryptionMethod XtsAes256 -UsedSpaceOnly -Pin $SecureString -TPMandPinProtector
```
## Related Articles
- [BitLocker: FAQs](bitlocker-frequently-asked-questions.yml)
- [Microsoft BitLocker Administration and Management (MBAM)](/microsoft-desktop-optimization-pack/mbam-v25/)
- [Overview of BitLocker Device Encryption in Windows](bitlocker-device-encryption-overview-windows-10.md#bitlocker-device-encryption)
- [BitLocker Group Policy Reference](./bitlocker-group-policy-settings.md)
- [Microsoft Intune](https://www.microsoft.com/cloud-platform/microsoft-intune/)
*(Overview)*
- [Configuration Settings Providers](/windows/client-management/mdm/policy-configuration-service-provider)
*(Policy CSP: See [Security-RequireDeviceEncryption](/windows/client-management/mdm/policy-csp-security#security-policies))*
- [BitLocker CSP](/windows/client-management/mdm/bitlocker-csp/)
### Windows Server setup tools
- [Windows Server Installation Options](/windows-server/get-started-19/install-upgrade-migrate-19/)
- [How to update local source media to add roles and features](/archive/blogs/joscon/how-to-update-local-source-media-to-add-roles-and-features)
- [How to add or remove optional components on Server Core](/archive/blogs/server_core/using-features-on-demand-with-updated-systems-and-patched-images) *(Features on Demand)*
- [BitLocker: How to deploy on Windows Server 2012 and newer](bitlocker-how-to-deploy-on-windows-server.md)
- [BitLocker: How to enable Network Unlock](bitlocker-how-to-enable-network-unlock.md)
- [Shielded VMs and Guarded Fabric](https://blogs.technet.microsoft.com/windowsserver/2016/05/10/a-closer-look-at-shielded-vms-in-windows-server-2016/)
### PowerShell
- [BitLocker cmdlets for Windows PowerShell](bitlocker-use-bitlocker-drive-encryption-tools-to-manage-bitlocker.md#bitlocker-cmdlets-for-windows-powershell)
- [Surface Pro Specifications](https://www.microsoft.com/surface/support/surface-pro-specs/)

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### YamlMime:FAQ
metadata:
title: BitLocker Network Unlock FAQ (Windows 10)
description: Familiarize yourself with BitLocker Network Unlock. Learn how it can make desktop and server management easier within domain environments.
ms.prod: windows-client
ms.technology: itpro-security
author: frankroj
ms.author: frankroj
manager: aaroncz
audience: ITPro
ms.topic: faq
ms.date: 11/08/2022
title: BitLocker Network Unlock FAQ
summary: |
sections:
- name: Ignored
questions:
- question: |
BitLocker Network Unlock FAQ
answer: |
BitLocker Network Unlock enables easier management for BitLocker-enabled desktops and servers that use the TPM+PIN protection method in a domain environment. When a computer that is connected to a wired corporate network is rebooted, Network Unlock allows the PIN entry prompt to be bypassed. It automatically unlocks BitLocker-protected operating system volumes by using a trusted key that is provided by the Windows Deployment Services server as its secondary authentication method.
To use Network Unlock, a PIN must be configured for the computer. When the computer isn't connected to the network, a PIN will need to be provided to unlock it.
BitLocker Network Unlock has software and hardware requirements for both client computers, Windows Deployment services, and domain controllers that must be met before it can be used.
Network Unlock uses two protectors - the TPM protector and the protector provided by the network or by the PIN. Automatic unlock uses a single protector - the one stored in the TPM. If the computer is joined to a network without the key protector, it will prompt to enter a PIN. If the PIN isn't available, the recovery key will need to be used to unlock the computer if it can't be connected to the network.
For more info, see [BitLocker: How to enable Network Unlock](bitlocker-how-to-enable-network-unlock.md).

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### YamlMime:FAQ
metadata:
title: BitLocker overview and requirements FAQ (Windows 10)
description: This article for IT professionals answers frequently asked questions concerning the requirements to use BitLocker.
ms.prod: windows-client
ms.technology: itpro-security
author: frankroj
ms.author: frankroj
manager: aaroncz
ms.collection:
- highpri
- tier1
ms.topic: faq
ms.date: 11/08/2022
title: BitLocker Overview and Requirements FAQ
summary: |
sections:
- name: Ignored
questions:
- question: How does BitLocker work?
answer: |
**How BitLocker works with operating system drives**
BitLocker Can be used to mitigate unauthorized data access on lost or stolen computers by encrypting all user files and system files on the operating system drive, including the swap files and hibernation files, and checking the integrity of early boot components and boot configuration data.
**How BitLocker works with fixed and removable data drives**
BitLocker can be used to encrypt the entire contents of a data drive. Group Policy can be used to require BitLocker be enabled on a drive before the computer can write data to the drive. BitLocker can be configured with various unlock methods for data drives, and a data drive supports multiple unlock methods.
- question: Does BitLocker support multifactor authentication?
answer: Yes, BitLocker supports multifactor authentication for operating system drives. If BitLocker is enabled on a computer that has a TPM version 1.2 or later, additional forms of authentication can be used with the TPM protection.
- question: What are the BitLocker hardware and software requirements?
answer: |
For requirements, see [System requirements](bitlocker-overview.md#system-requirements).
> [!NOTE]
> Dynamic disks aren't supported by BitLocker. Dynamic data volumes won't be displayed in the Control Panel. Although the operating system volume will always be displayed in the Control Panel, regardless of whether it's a Dynamic disk, if it's a dynamic disk it can't be protected by BitLocker.
- question: Why are two partitions required? Why does the system drive have to be so large?
answer: Two partitions are required to run BitLocker because pre-startup authentication and system integrity verification must occur on a separate partition from the encrypted operating system drive. This configuration helps protect the operating system and the information in the encrypted drive.
- question: Which Trusted Platform Modules (TPMs) does BitLocker support?
answer: |
BitLocker supports TPM version 1.2 or higher. BitLocker support for TPM 2.0 requires Unified Extensible Firmware Interface (UEFI) for the device.
> [!NOTE]
> TPM 2.0 isn't supported in Legacy and CSM Modes of the BIOS. Devices with TPM 2.0 must have their BIOS mode configured as Native UEFI only. The Legacy and Compatibility Support Module (CSM) options must be disabled. For added security, enable the Secure Boot feature.
>
> Installed Operating System on hardware in legacy mode will stop the OS from booting when the BIOS mode is changed to UEFI. Use the tool [MBR2GPT](/windows/deployment/mbr-to-gpt) before changing the BIOS mode that will prepare the OS and the disk to support UEFI.
- question: How can I tell if a computer has a TPM?
answer: Beginning with Windows 10, version 1803, the TPM status can be checked in **Windows Defender Security Center** > **Device Security** > **Security processor details**. In previous versions of Windows, open the TPM MMC console (tpm.msc) and look under the **Status** heading. [**Get-TPM**](/powershell/module/trustedplatformmodule/get-tpm?view=windowsserver2019-ps)** can also be run in PowerShell to get more details about the TPM on the current computer.
- question: Can I use BitLocker on an operating system drive without a TPM?
answer: |
Yes, BitLocker can be enabled on an operating system drive without a TPM version 1.2 or higher, if the BIOS or UEFI firmware has the ability to read from a USB flash drive in the boot environment. BitLocker won't unlock the protected drive until BitLocker's own volume master key is first released by either the computer's TPM or by a USB flash drive containing the BitLocker startup key for that computer. However, computers without TPMs won't be able to use the system integrity verification that BitLocker can also provide.
To help determine whether a computer can read from a USB device during the boot process, use the BitLocker system check as part of the BitLocker setup process. This system check performs tests to confirm that the computer can properly read from the USB devices at the appropriate time and that the computer meets other BitLocker requirements.
- question: How do I obtain BIOS support for the TPM on my computer?
answer: |
Contact the computer manufacturer to request a Trusted Computing Group (TCG)-compliant BIOS or UEFI boot firmware that meets the following requirements:
- It's compliant with the TCG standards for a client computer.
- It has a secure update mechanism to help prevent a malicious BIOS or boot firmware from being installed on the computer.
- question: What credentials are required to use BitLocker?
answer: To turn on, turn off, or change configurations of BitLocker on operating system and fixed data drives, membership in the local **Administrators** group is required. Standard users can turn on, turn off, or change configurations of BitLocker on removable data drives.
- question: What is the recommended boot order for computers that are going to be BitLocker-protected?
answer: The computer's startup options should be configured to have the hard disk drive first in the boot order, before any other drives such as CD/DVD drives or USB drives. If the hard disk isn't first and the computer typically boots from the hard disk, then a boot order change may be detected or assumed when removable media is found during boot. The boot order typically affects the system measurement that is verified by BitLocker and a change in boot order will cause a prompt for the BitLocker recovery key. For the same reason, if a laptop is used with a docking station, ensure that the hard disk drive is first in the boot order both when the laptop is docked and undocked.

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---
title: BitLocker overview
description: This article provides a high-level overview of BitLocker, including a list of system requirements, practical applications, and deprecated features.
ms.collection:
- highpri
- tier1
ms.topic: conceptual
ms.date: 11/08/2022
---
# BitLocker overview
This article provides a high-level overview of BitLocker, including a list of system requirements, practical applications, and deprecated features.
BitLocker Drive Encryption is a data protection feature that integrates with the operating system and addresses the threats of data theft or exposure from lost, stolen, or inappropriately decommissioned computers.
BitLocker provides the maximum protection when used with a Trusted Platform Module (TPM) version 1.2 or later versions. The TPM is a hardware component installed in many newer computers by the computer manufacturers. It works with BitLocker to help protect user data and to ensure that a computer hasn't been tampered with while the system was offline.
On computers that don't have a TPM version 1.2 or later versions, BitLocker can still be used to encrypt the Windows operating system drive. However, this implementation requires the user to insert a USB startup key to start the computer or resume from hibernation. Starting with Windows 8, an operating system volume password can be used to protect the operating system volume on a computer without TPM. Both options don't provide the pre-startup system integrity verification offered by BitLocker with a TPM.
In addition to the TPM, BitLocker offers the option to lock the normal startup process until the user supplies a personal identification number (PIN) or inserts a removable device (such as a USB flash drive) that contains a startup key. These additional security measures provide multifactor authentication and assurance that the computer won't start or resume from hibernation until the correct PIN or startup key is presented.
## Practical applications
Data on a lost or stolen computer is vulnerable to unauthorized access, either by running a software-attack tool against it or by transferring the computer's hard disk to a different computer. BitLocker helps mitigate unauthorized data access by enhancing file and system protections. BitLocker also helps render data inaccessible when BitLocker-protected computers are decommissioned or recycled.
There are two additional tools in the Remote Server Administration Tools that can be used to manage BitLocker.
- **BitLocker Recovery Password Viewer**. The BitLocker Recovery Password Viewer enables the BitLocker Drive Encryption recovery passwords that have been backed up to Active Directory Domain Services (AD DS) to be located and viewed. This tool can be used to help recover data that is stored on a drive that has been encrypted by using BitLocker. The BitLocker Recovery Password Viewer tool is an extension for the Active Directory Users and Computers Microsoft Management Console (MMC) snap-in.
By using this tool, a computer object's **Properties** dialog box can be examined to view the corresponding BitLocker recovery passwords. Additionally, a domain container can be searched for a BitLocker recovery password across all the domains in the Active Directory forest by right clicking on the domain container. Viewing recovery passwords can only be viewed by domain administrator or having delegated permissions by a domain administrator.
- **BitLocker Drive Encryption Tools**. BitLocker Drive Encryption Tools include the command-line tools, manage-bde and repair-bde, and the BitLocker cmdlets for Windows PowerShell. Both manage-bde and the BitLocker cmdlets can be used to perform any task that can be accomplished through the
BitLocker control panel, and they're appropriate to be used for automated deployments and other scripting scenarios. Repair-bde is provided for disaster recovery scenarios in which a BitLocker-protected drive can't be unlocked normally or by using the recovery console.
[!INCLUDE [bitlocker](../../../../../includes/licensing/bitlocker-enablement.md)]
## System requirements
BitLocker has the following hardware requirements:
For BitLocker to use the system integrity check provided by a TPM, the computer must have TPM 1.2 or later versions. If a computer doesn't have a TPM, saving a startup key on a removable drive, such as a USB flash drive, becomes mandatory when enabling BitLocker.
A computer with a TPM must also have a Trusted Computing Group (TCG)-compliant BIOS or UEFI firmware. The BIOS or UEFI firmware establishes a chain of trust for the pre-operating system startup, and it must include support for TCG-specified Static Root of Trust Measurement. A computer without a TPM doesn't require TCG-compliant firmware.
The system BIOS or UEFI firmware (for TPM and non-TPM computers) must support the USB mass storage device class, including reading small files on a USB flash drive in the pre-operating system environment.
> [!IMPORTANT]
> From Windows 7, an OS drive can be encrypted without a TPM and USB flash drive. For this procedure, see [Tip of the Day: Bitlocker without TPM or USB](https://social.technet.microsoft.com/Forums/en-US/eac2cc67-8442-42db-abad-2ed173879751/bitlocker-without-tpm?forum=win10itprosetup).
> [!NOTE]
> TPM 2.0 is not supported in Legacy and Compatibility Support Module (CSM) modes of the BIOS. Devices with TPM 2.0 must have their BIOS mode configured as native UEFI only. The Legacy and CSM options must be disabled. For added security, enable the secure boot feature.
> Installed Operating System on hardware in Legacy mode stops the OS from booting when the BIOS mode is changed to UEFI. Use the tool [MBR2GPT](/windows/deployment/mbr-to-gpt) before changing the BIOS mode, which prepares the OS and the disk to support UEFI.
The hard disk must be partitioned with at least two drives:
- The operating system drive (or boot drive) contains the operating system and its support files. It must be formatted with the NTFS file system.
- The system drive contains the files that are needed to load Windows after the firmware has prepared the system hardware. BitLocker isn't enabled on this drive. For BitLocker to work, the system drive must not be encrypted, must differ from the operating system drive, and must be formatted with the FAT32 file system on computers that use UEFI-based firmware or with the NTFS file system on computers that use BIOS firmware. It's recommended that the system drive be approximately 350 MB in size. After BitLocker is turned on, it should have approximately 250 MB of free space.
When installed on a new computer, Windows automatically creates the partitions that are required for BitLocker.
A partition subject to encryption can't be marked as an active partition. This requirement applies to the operating system drives, fixed data drives, and removable data drives.
When installing the BitLocker optional component on a server, the Enhanced Storage feature also needs to be installed. The Enhanced Storage feature is used to support hardware encrypted drives.
## In this section
| Article | Description |
| - | - |
| [Overview of BitLocker Device Encryption in Windows 10](bitlocker-device-encryption-overview-windows-10.md) | This article provides an overview of the ways in which BitLocker Device Encryption can help protect data on devices running Windows 10. |
| [BitLocker frequently asked questions (FAQ)](bitlocker-frequently-asked-questions.yml) | This article answers frequently asked questions concerning the requirements to use, upgrade, deploy and administer, and key management policies for BitLocker.|
| [Prepare your organization for BitLocker: Planning and policies](prepare-your-organization-for-bitlocker-planning-and-policies.md)| This article explains the procedure you can use to plan your BitLocker deployment. |
| [BitLocker basic deployment](bitlocker-basic-deployment.md) | This article explains how BitLocker features can be used to protect your data through drive encryption. |
| [BitLocker: How to deploy on Windows Server](bitlocker-how-to-deploy-on-windows-server.md)| This article explains how to deploy BitLocker on Windows Server.|
| [BitLocker: How to enable Network Unlock](bitlocker-how-to-enable-network-unlock.md) | This article describes how BitLocker Network Unlock works and how to configure it. |
| [BitLocker: Use BitLocker Drive Encryption Tools to manage BitLocker](bitlocker-use-bitlocker-drive-encryption-tools-to-manage-bitlocker.md)| This article describes how to use tools to manage BitLocker.|
| [BitLocker: Use BitLocker Recovery Password Viewer](bitlocker-use-bitlocker-recovery-password-viewer.md) | This article describes how to use the BitLocker Recovery Password Viewer. |
| [BitLocker Group Policy settings](bitlocker-group-policy-settings.md) | This article describes the function, location, and effect of each group policy setting that is used to manage BitLocker. |
| [BCD settings and BitLocker](bcd-settings-and-bitlocker.md) | This article describes the BCD settings that are used by BitLocker.|
| [BitLocker Recovery Guide](bitlocker-recovery-guide-plan.md)| This article describes how to recover BitLocker keys from AD DS. |
| [Protect BitLocker from pre-boot attacks](./bitlocker-countermeasures.md)| This detailed guide helps you understand the circumstances under which the use of pre-boot authentication is recommended for devices running Windows 10, Windows 8.1, Windows 8, or Windows 7; and when it can be safely omitted from a device's configuration. |
| [Troubleshoot BitLocker](/troubleshoot/windows-client/windows-security/bitlocker-issues-troubleshooting) | This guide describes the resources that can help you troubleshoot BitLocker issues, and provides solutions for several common BitLocker issues. |
| [Protecting cluster shared volumes and storage area networks with BitLocker](protecting-cluster-shared-volumes-and-storage-area-networks-with-bitlocker.md)| This article describes how to protect CSVs and SANs with BitLocker.|
| [Enabling Secure Boot and BitLocker Device Encryption on Windows IoT Core](/windows/iot-core/secure-your-device/SecureBootAndBitLocker) | This article describes how to use BitLocker with Windows IoT Core |

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---
title: BitLocker recovery guide
description: This article for IT professionals describes how to recover BitLocker keys from Active Directory Domain Services (AD DS).
ms.collection:
- highpri
- tier1
ms.topic: conceptual
ms.date: 11/08/2022
---
# BitLocker recovery guide
This article describes how to recover BitLocker keys from AD DS.
Organizations can use BitLocker recovery information saved in Active Directory Domain Services (AD DS) to access BitLocker-protected data. It's recommended to create a recovery model for BitLocker while planning for BitLocker deployment.
This article assumes that it's understood how to set up AD DS to back up BitLocker recovery information automatically, and what types of recovery information are saved to AD DS.
This article doesn't detail how to configure AD DS to store the BitLocker recovery information.
## What is BitLocker recovery?
BitLocker recovery is the process by which access can be restored to a BitLocker-protected drive if the drive can't be unlocked normally. In a recovery scenario, the following options to restore access to the drive are available:
- **The user can supply the recovery password.** If the organization allows users to print or store recovery passwords, the users can enter in the 48-digit recovery password that they printed or stored on a USB drive or with a Microsoft account online. Saving a recovery password with a Microsoft account online is only allowed when BitLocker is used on a PC that isn't a member of a domain.
- **Data recovery agents can use their credentials to unlock the drive.** If the drive is an operating system drive, the drive must be mounted as a data drive on another computer for the data recovery agent to unlock it.
- **A domain administrator can obtain the recovery password from AD DS and use it to unlock the drive.** Storing recovery passwords in AD DS is recommended to provide a way for IT professionals to be able to obtain recovery passwords for drives in an organization if needed. This method makes it mandatory to enable this recovery method in the BitLocker group policy setting **Choose how BitLocker-protected operating system drives can be recovered** located at **Computer Configuration** > **Administrative Templates** > **Windows Components** > **BitLocker Drive Encryption** > **Operating System Drives** in the Local Group Policy Editor. For more information, see [BitLocker Group Policy settings](bitlocker-group-policy-settings.md).
### What causes BitLocker recovery?
The following list provides examples of specific events that will cause BitLocker to enter recovery mode when attempting to start the operating system drive:
- On PCs that use BitLocker Drive Encryption, or on devices such as tablets or phones that use [BitLocker Device Encryption](bitlocker-device-encryption-overview-windows-10.md) only, when an attack is detected, the device will immediately reboot and enter into BitLocker recovery mode. To take advantage of this functionality, administrators can set the **Interactive logon: Machine account lockout threshold** Group Policy setting located in **Computer Configuration** > **Windows Settings** > **Security Settings** > **Local Policies** > **Security Options** in the Local Group Policy Editor. Or they can use the **MaxFailedPasswordAttempts** policy of [Exchange ActiveSync](/Exchange/clients/exchange-activesync/exchange-activesync) (also configurable through [Microsoft Intune](/mem/intune)), to limit the number of failed password attempts before the device goes into Device Lockout.
- On devices with TPM 1.2, changing the BIOS or firmware boot device order causes BitLocker recovery. However, devices with TPM 2.0 don't start BitLocker recovery in this case. TPM 2.0 doesn't consider a firmware change of boot device order as a security threat because the OS Boot Loader isn't compromised.
- Having the CD or DVD drive before the hard drive in the BIOS boot order and then inserting or removing a CD or DVD.
- Failing to boot from a network drive before booting from the hard drive.
- Docking or undocking a portable computer. In some instances (depending on the computer manufacturer and the BIOS), the docking condition of the portable computer is part of the system measurement and must be consistent to validate the system status and unlock BitLocker. So if a portable computer is connected to its docking station when BitLocker is turned on, then it might also need to be connected to the docking station when it's unlocked. Conversely, if a portable computer isn't connected to its docking station when BitLocker is turned on, then it might need to be disconnected from the docking station when it's unlocked.
- Changes to the NTFS partition table on the disk including creating, deleting, or resizing a primary partition.
- Entering the personal identification number (PIN) incorrectly too many times so that the anti-hammering logic of the TPM is activated. Anti-hammering logic is software or hardware methods that increase the difficulty and cost of a brute force attack on a PIN by not accepting PIN entries until after a certain amount of time has passed.
- Turning off the support for reading the USB device in the pre-boot environment from the BIOS or UEFI firmware if using USB-based keys instead of a TPM.
- Turning off, disabling, deactivating, or clearing the TPM.
- Upgrading critical early startup components, such as a BIOS or UEFI firmware upgrade, causing the related boot measurements to change.
- Forgetting the PIN when PIN authentication has been enabled.
- Updating option ROM firmware.
- Upgrading TPM firmware.
- Adding or removing hardware; for example, inserting a new card in the computer, including some PCMIA wireless cards.
- Removing, inserting, or completely depleting the charge on a smart battery on a portable computer.
- Changes to the master boot record on the disk.
- Changes to the boot manager on the disk.
- Hiding the TPM from the operating system. Some BIOS or UEFI settings can be used to prevent the enumeration of the TPM to the operating system. When implemented, this option can make the TPM hidden from the operating system. When the TPM is hidden, BIOS and UEFI secure startup are disabled, and the TPM doesn't respond to commands from any software.
- Using a different keyboard that doesn't correctly enter the PIN or whose keyboard map doesn't match the keyboard map assumed by the pre-boot environment. This problem can prevent the entry of enhanced PINs.
- Modifying the Platform Configuration Registers (PCRs) used by the TPM validation profile. For example, including **PCR\[1\]** would result in BitLocker measuring most changes to BIOS settings, causing BitLocker to enter recovery mode even when non-boot critical BIOS settings change.
> [!NOTE]
> Some computers have BIOS settings that skip measurements to certain PCRs, such as **PCR\[2\]**. Changing this setting in the BIOS would cause BitLocker to enter recovery mode because the PCR measurement will be different.
- Moving the BitLocker-protected drive into a new computer.
- Upgrading the motherboard to a new one with a new TPM.
- Losing the USB flash drive containing the startup key when startup key authentication has been enabled.
- Failing the TPM self-test.
- Having a BIOS, UEFI firmware, or an option ROM component that isn't compliant with the relevant Trusted Computing Group standards for a client computer. For example, a non-compliant implementation may record volatile data (such as time) in the TPM measurements, causing different measurements on each startup and causing BitLocker to start in recovery mode.
- Changing the usage authorization for the storage root key of the TPM to a non-zero value.
> [!NOTE]
> The BitLocker TPM initialization process sets the usage authorization value to zero, so another user or process must explicitly have changed this value.
- Disabling the code integrity check or enabling test signing on Windows Boot Manager (Bootmgr).
- Pressing the F8 or F10 key during the boot process.
- Adding or removing add-in cards (such as video or network cards), or upgrading firmware on add-in cards.
- Using a BIOS hot key during the boot process to change the boot order to something other than the hard drive.
> [!NOTE]
> Before beginning recovery, it is recommend to determine what caused recovery. This might help prevent the problem from occurring again in the future. For instance, if it is determined that an attacker has modified the computer by obtaining physical access, new security policies can be created for tracking who has physical presence. After the recovery password has been used to recover access to the PC, BitLocker reseals the encryption key to the current values of the measured components.
For planned scenarios, such as a known hardware or firmware upgrades, initiating recovery can be avoided by temporarily suspending BitLocker protection. Because suspending BitLocker leaves the drive fully encrypted, the administrator can quickly resume BitLocker protection after the planned task has been completed. Using suspend and resume also reseals the encryption key without requiring the entry of the recovery key.
> [!NOTE]
> If suspended BitLocker will automatically resume protection when the PC is rebooted, unless a reboot count is specified using the manage-bde command line tool.
If software maintenance requires the computer to be restarted and two-factor authentication is being used, the BitLocker network unlock feature can be enabled to provide the secondary authentication factor when the computers don't have an on-premises user to provide the additional authentication method.
Recovery has been described within the context of unplanned or undesired behavior. However, recovery can also be caused as an intended production scenario, for example in order to manage access control. When desktop or laptop computers are redeployed to other departments or employees in the enterprise, BitLocker can be forced into recovery before the computer is given to a new user.
## Testing recovery
Before a thorough BitLocker recovery process is created, it's recommended to test how the recovery process works for both end users (people who call the helpdesk for the recovery password) and administrators (people who help the end user get the recovery password). The `-forcerecovery` command of `manage-bde.exe` is an easy way to step through the recovery process before users encounter a recovery situation.
**To force a recovery for the local computer:**
1. Select the **Start** button and type in **cmd**
2. Right select on **cmd.exe** or **Command Prompt** and then select **Run as administrator**.
3. At the command prompt, enter the following command:
```cmd
manage-bde.exe -forcerecovery <BitLockerVolume>
```
**To force recovery for a remote computer:**
1. Select the **Start** button and type in **cmd**
2. Right select on **cmd.exe** or **Command Prompt** and then select **Run as administrator**.
3. At the command prompt, enter the following command:
```cmd
manage-bde.exe -ComputerName <RemoteComputerName> -forcerecovery <BitLockerVolume>
```
> [!NOTE]
> Recovery triggered by `-forcerecovery` persists for multiple restarts until a TPM protector is added or protection is suspended by the user. When using Modern Standby devices (such as Surface devices), the `-forcerecovery` option is not recommended because BitLocker will have to be unlocked and disabled manually from the WinRE environment before the OS can boot up again. For more information, see [BitLocker Troubleshooting: Continuous reboot loop with BitLocker recovery on a slate device](https://social.technet.microsoft.com/wiki/contents/articles/18671.bitlocker-troubleshooting-continuous-reboot-loop-with-bitlocker-recovery-on-a-slate-device.aspx).
## Planning the recovery process
When planning the BitLocker recovery process, first consult the organization's current best practices for recovering sensitive information. For example: How does the enterprise handle lost Windows passwords? How does the organization perform smart card PIN resets? These best practices and related resources (people and tools) can be used to help formulate a BitLocker recovery model.
Organizations that rely on BitLocker Drive Encryption and BitLocker To Go to protect data on a large number of computers and removable drives running the Windows 11, Windows 10, Windows 8, or Windows 7 operating systems and Windows to Go should consider using the Microsoft BitLocker Administration and Monitoring (MBAM) Tool version 2.0, which is included in the Microsoft Desktop Optimization Pack (MDOP) for Microsoft Software Assurance. MBAM makes BitLocker implementations easier to deploy and manage and allows administrators to provision and monitor encryption for operating system and fixed drives. MBAM prompts the user before encrypting fixed drives. MBAM also manages recovery keys for fixed and removable drives, making recovery easier to manage. MBAM can be used as part of a Microsoft System Center deployment or as a stand-alone solution. For more info, see [Microsoft BitLocker Administration and Monitoring](/microsoft-desktop-optimization-pack/mbam-v25/).
After a BitLocker recovery has been initiated, users can use a recovery password to unlock access to encrypted data. Consider both self-recovery and recovery password retrieval methods for the organization.
When the recovery process is determined:
- Become familiar with how a recovery password can be retrieved. See:
- [Self-recovery](#self-recovery)
- [Recovery password retrieval](#recovery-password-retrieval)
- Determine a series of steps for post-recovery, including analyzing why the recovery occurred and resetting the recovery password. See:
- [Post-recovery analysis](#post-recovery-analysis)
### Self-recovery
In some cases, users might have the recovery password in a printout or a USB flash drive and can perform self-recovery. It's recommended that the organization creates a policy for self-recovery. If self-recovery includes using a password or recovery key stored on a USB flash drive, the users must be warned not to store the USB flash drive in the same place as the PC, especially during travel. For example, if both the PC and the recovery items are in the same bag it would be easy for access to be gained to the PC by an unauthorized user. Another policy to consider is having users contact the Helpdesk before or after performing self-recovery so that the root cause can be identified.
### Recovery password retrieval
If the user doesn't have a recovery password printed or on a USB flash drive, the user will need to be able to retrieve the recovery password from an online source. If the PC is a member of a domain, the recovery password can be backed up to AD DS. **However, back up of the recovery password to AD DS does not happen by default.** Backup of the recovery password to AD DS has to be configured via the appropriate group policy settings **before** BitLocker was enabled on the PC. BitLocker group policy settings can be found in the Local Group Policy Editor or the Group Policy Management Console (GPMC) under **Computer Configuration** > **Administrative Templates** > **Windows Components** > **BitLocker Drive Encryption**. The following policy settings define the recovery methods that can be used to restore access to a BitLocker-protected drive if an authentication method fails or is unable to be used.
- **Choose how BitLocker-protected operating system drives can be recovered**
- **Choose how BitLocker-protected fixed drives can be recovered**
- **Choose how BitLocker-protected removable drives can be recovered**
In each of these policies, select **Save BitLocker recovery information to Active Directory Domain Services** and then choose which BitLocker recovery information to store in AD DS. Check the **Do not enable BitLocker until recovery information is stored in AD
DS** check box if it's desired to prevent users from enabling BitLocker unless the computer is connected to the domain and the backup of BitLocker recovery information for the drive to AD DS succeeds.
> [!NOTE]
> If the PCs are part of a workgroup, users are advised to save their BitLocker recovery password with their Microsoft account online. Having an online copy of the BitLocker recovery password is recommended to help ensure access to data is not lost in the event of a recovery being required.
The BitLocker Recovery Password Viewer for Active Directory Users and Computers tool allows domain administrators to view BitLocker recovery passwords for specific computer objects in Active Directory.
The following list can be used as a template for creating a recovery process for recovery password retrieval. This sample process uses the BitLocker Recovery Password Viewer for Active Directory Users and Computers tool.
- [Record the name of the user's computer](#record-the-name-of-the-users-computer)
- [Verify the user's identity](#verify-the-users-identity)
- [Locate the recovery password in AD DS](#locate-the-recovery-password-in-ad-ds)
- [Gather information to determine why recovery occurred](#gather-information-to-determine-why-recovery-occurred)
- [Give the user the recovery password](#give-the-user-the-recovery-password)
### Record the name of the user's computer
The name of the user's computer can be used to locate the recovery password in AD DS. If the user doesn't know the name of the computer, ask the user to read the first word of the **Drive Label** in the **BitLocker Drive Encryption Password Entry** user interface. This word is the computer name when BitLocker was enabled and is probably the current name of the computer.
### Verify the user's identity
The person who is asking for the recovery password should be verified as the authorized user of that computer. It should also be verified whether the computer for which the user provided the name belongs to the user.
### Locate the recovery password in AD DS
Locate the computer object with the matching name in AD DS. Because computer object names are listed in the AD DS global catalog, the object should be able to be located even if it's a multi-domain forest.
### Multiple recovery passwords
If multiple recovery passwords are stored under a computer object in AD DS, the name of the BitLocker recovery information object includes the date on which the password was created.
To make sure the correct password is provided and/or to prevent providing the incorrect password, ask the user to read the eight character password ID that is displayed in the recovery console.
Since the password ID is a unique value that is associated with each recovery password stored in AD DS, running a query using this ID finds the correct password to unlock the encrypted volume.
### Gather information to determine why recovery occurred
Before giving the user the recovery password, information should be gatherer that will help determine why the recovery was needed. This information can be used to analyze the root cause during the post-recovery analysis. For more information about post-recovery analysis, see [Post-recovery analysis](#post-recovery-analysis).
### Give the user the recovery password
Because the recovery password is 48 digits long, the user may need to record the password by writing it down or typing it on a different computer. If using MBAM or Configuration Manager BitLocker Management, the recovery password will be regenerated after it's recovered from the MBAM or Configuration Manager database to avoid the security risks associated with an uncontrolled password.
> [!NOTE]
> Because the 48-digit recovery password is long and contains a combination of digits, the user might mishear or mistype the password. The boot-time recovery console uses built-in checksum numbers to detect input errors in each 6-digit block of the 48-digit recovery password, and offers the user the opportunity to correct such errors.
### Post-recovery analysis
When a volume is unlocked using a recovery password, an event is written to the event log, and the platform validation measurements are reset in the TPM to match the current configuration. Unlocking the volume means that the encryption key has been released and is ready for on-the-fly encryption when data is written to the volume, and on-the-fly decryption when data is read from the volume. After the volume is unlocked, BitLocker behaves the same way, regardless of how the access was granted.
If it's noticed that a computer is having repeated recovery password unlocks, an administrator might want to perform post-recovery analysis to determine the root cause of the recovery, and refresh BitLocker platform validation so that the user no longer needs to enter a recovery password each time that the computer starts up. For more information, see:
- [Determine the root cause of the recovery](#determine-the-root-cause-of-the-recovery)
- [Resolve the root cause](#resolve-the-root-cause)
### Determine the root cause of the recovery
If a user needed to recover the drive, it's important to determine the root cause that initiated the recovery as soon as possible. Properly analyzing the state of the computer and detecting tampering may reveal threats that have broader implications for enterprise security.
While an administrator can remotely investigate the cause of recovery in some cases, the end user might need to bring the computer that contains the recovered drive on site to analyze the root cause further.
Review and answer the following questions for the organization:
1. Which BitLocker protection mode is in effect (TPM, TPM + PIN, TPM + startup key, startup key only)? Which PCR profile is in use on the PC?
2. Did the user merely forget the PIN or lose the startup key? If a token was lost, where might the token be?
3. If TPM mode was in effect, was recovery caused by a boot file change?
4. If recovery was caused by a boot file change, is the boot file change due to an intended user action (for example, BIOS upgrade), or a malicious software?
5. When was the user last able to start the computer successfully, and what might have happened to the computer since then?
6. Might the user have encountered malicious software or left the computer unattended since the last successful startup?
To help answer these questions, use the BitLocker command-line tool to view the current configuration and protection mode:
```cmd
manage-bde.exe -status
```
Scan the event log to find events that help indicate why recovery was initiated (for example, if a boot file change occurred). Both of these capabilities can be performed remotely.
### Resolve the root cause
After it has been identified what caused recovery, BitLocker protection can be reset to avoid recovery on every startup.
The details of this reset can vary according to the root cause of the recovery. If root cause can't be determined, or if a malicious software or a rootkit might have infected the computer, Helpdesk should apply best-practice virus policies to react appropriately.
> [!NOTE]
> BitLocker validation profile reset can be performed by suspending and resuming BitLocker.
- [Unknown PIN](#unknown-pin)
- [Lost startup key](#lost-startup-key)
- [Changes to boot files](#changes-to-boot-files)
### Unknown PIN
If a user has forgotten the PIN, the PIN must be reset while signed on to the computer in order to prevent BitLocker from initiating recovery each time the computer is restarted.
#### To prevent continued recovery due to an unknown PIN
1. Unlock the computer using the recovery password.
2. Reset the PIN:
1. Select and hold the drive and then select **Change PIN**
2. In the BitLocker Drive Encryption dialog, select **Reset a forgotten PIN**. If the signed in account isn't an administrator account, administrative credentials must be provided at this time.
3. In the PIN reset dialog, provide and confirm the new PIN to be used and then select **Finish**.
3. The new PIN can be used the next time the drive needs to be unlocked.
### Lost startup key
If the USB flash drive that contains the startup key has been lost, then drive must be unlocked by using the recovery key. A new startup can then be created.
#### To prevent continued recovery due to a lost startup key
1. Sign in as an administrator to the computer that has its startup key lost.
2. Open Manage BitLocker.
3. Select **Duplicate start up key**, insert the clean USB drive where the key will be written, and then select **Save**.
### Changes to boot files
This error occurs if the firmware is updated. As a best practice, BitLocker should be suspended before making changes to the firmware. Protection should then be resumed after the firmware update has completed. Suspending BitLocker prevents the computer from going into recovery mode. However, if changes were made when BitLocker protection was on, the recovery password can be used to unlock the drive and the platform validation profile will be updated so that recovery won't occur the next time.
## Windows RE and BitLocker Device Encryption
Windows Recovery Environment (RE) can be used to recover access to a drive protected by [BitLocker Device Encryption](bitlocker-device-encryption-overview-windows-10.md). If a PC is unable to boot after two failures, Startup Repair automatically starts. When Startup Repair is launched automatically due to boot failures, it executes only operating system and driver file repairs if the boot logs or any available crash dump points to a specific corrupted file. In Windows 8.1 and later versions, devices that include firmware to support specific TPM measurements for PCR\[7\] **the TPM** can validate that Windows RE is a trusted operating environment and unlock any BitLocker-protected drives if Windows RE hasn't been modified. If the Windows RE environment has been modified, for example, the TPM has been disabled, the drives stay locked until the BitLocker recovery key is provided. If Startup Repair isn't able to run automatically from the PC and instead, Windows RE is manually started from a repair disk, the BitLocker recovery key must be provided to unlock the BitLocker-protected drives.
Windows RE will also ask for a BitLocker recovery key when a **Remove everything** reset from Windows RE is started on a device that uses **TPM + PIN** or **Password for OS drive** protectors. If BitLocker recovery is started on a keyboardless device with TPM-only protection, Windows RE, not the boot manager, will ask for the BitLocker recovery key. After the key is entered, Windows RE troubleshooting tools can be accessed, or Windows can be started normally.
The BitLocker recovery screen that's shown by Windows RE has the accessibility tools like narrator and on-screen keyboard to help enter the BitLocker recovery key. If the BitLocker recovery key is requested by the Windows boot manager, those tools might not be available.
To activate the narrator during BitLocker recovery in Windows RE, press **Windows** + **CTRL** + **Enter**. To activate the on-screen keyboard, tap on a text input control.
:::image type="content" source="images/bl-narrator.png" alt-text="A screenshot of the BitLocker recovery screen showing Narrator activated.":::
## BitLocker recovery screen
During BitLocker recovery, Windows displays a custom recovery message and a few hints that identify where a key can be retrieved from. These improvements can help a user during BitLocker recovery.
### Custom recovery message
BitLocker Group Policy settings starting in Windows 10, version 1511, allows configuring a custom recovery message and URL on the BitLocker recovery screen. The custom recovery message and URL can include the address of the BitLocker self-service recovery portal, the IT internal website, or a phone number for support.
This policy can be configured using GPO under **Computer Configuration** > **Administrative Templates** > **Windows Components** > **BitLocker Drive Encryption** > **Operating System Drives** > **Configure pre-boot recovery message and URL**.
It can also be configured using mobile device management (MDM), including in Intune, using the [BitLocker CSP](/windows/client-management/mdm/bitlocker-csp):
**`<LocURI>./Device/Vendor/MSFT/BitLocker/SystemDrivesRecoveryMessage</LocURI>`**
![Custom URL.](./images/bl-intune-custom-url.png)
Example of a customized recovery screen:
![Customized BitLocker Recovery Screen.](./images/bl-password-hint1.png)
### BitLocker recovery key hints
BitLocker metadata has been enhanced starting in Windows 10, version 1903, to include information about when and where the BitLocker recovery key was backed up. This information isn't exposed through the UI or any public API. It's used solely by the BitLocker recovery screen in the form of hints to help a user locate a volume's recovery key. Hints are displayed on the recovery screen and refer to the location where the key has been saved. Hints are displayed on both the modern (blue) and legacy (black) recovery screen. The hints apply to both the boot manager recovery screen and the WinRE unlock screen.
![Customized BitLocker recovery screen.](./images/bl-password-hint2.png)
> [!IMPORTANT]
> It is not recommend to print recovery keys or saving them to a file. Instead, use Active Directory backup or a cloud-based backup. Cloud-based backup includes Azure Active Directory (Azure AD) and Microsoft account.
There are rules governing which hint is shown during the recovery (in the order of processing):
1. Always display custom recovery message if it has been configured (using GPO or MDM).
2. Always display generic hint: `For more information, go to https://aka.ms/recoverykeyfaq.`
3. If multiple recovery keys exist on the volume, prioritize the last-created (and successfully backed up) recovery key.
4. Prioritize keys with successful backup over keys that have never been backed up.
5. Prioritize backup hints in the following order for remote backup locations: **Microsoft Account > Azure AD > Active Directory**.
6. If a key has been printed and saved to file, display a combined hint, "Look for a printout or a text file with the key," instead of two separate hints.
7. If multiple backups of the same type (remove vs. local) have been performed for the same recovery key, prioritize backup info with latest backed-up date.
8. There's no specific hint for keys saved to an on-premises Active Directory. In this case, a custom message (if configured) or a generic message, "Contact your organization's help desk," is displayed.
9. If two recovery keys are present on the disk, but only one has been successfully backed up, the system asks for a key that has been backed up, even if another key is newer.
#### Example 1 (single recovery key with single backup)
| Custom URL | Yes |
|----------------------|------------|
| Saved to Microsoft Account | Yes |
| Saved to Azure AD | No |
| Saved to Active Directory | No |
| Printed | No |
| Saved to file | No |
**Result:** The hints for the Microsoft account and custom URL are displayed.
![Example 1 of Customized BitLocker recovery screen.](./images/rp-example1.png)
#### Example 2 (single recovery key with single backup)
| Custom URL | Yes |
|----------------------|------------|
| Saved to Microsoft Account | No |
| Saved to Azure AD | No |
| Saved to Active Directory | Yes |
| Printed | No |
| Saved to file | No |
**Result:** Only the custom URL is displayed.
![Example 2 of customized BitLocker recovery screen.](./images/rp-example2.png)
#### Example 3 (single recovery key with multiple backups)
| Custom URL | No |
|----------------------|------------|
| Saved to Microsoft Account | Yes |
| Saved to Azure AD | Yes |
| Saved to Active Directory | No |
| Printed | Yes |
| Saved to file | Yes |
**Result:** Only the Microsoft Account hint is displayed.
![Example 3 of customized BitLocker recovery screen.](./images/rp-example3.png)
#### Example 4 (multiple recovery passwords)
| Custom URL | No |
|----------------------|-----------------|
| Saved to Microsoft Account | No |
| Saved to Azure AD | No |
| Saved to Active Directory | No |
| Printed | No |
| Saved to file | Yes |
| Creation time | **1PM** |
| Key ID | A564F193 |
<br>
<br>
| Custom URL | No |
|----------------------|-----------------|
| Saved to Microsoft Account | No |
| Saved to Azure AD | No |
| Saved to Active Directory | No |
| Printed | No |
| Saved to file | No |
| Creation time | **3PM** |
| Key ID | T4521ER5 |
**Result:** Only the hint for a successfully backed up key is displayed, even if it isn't the most recent key.
![Example 4 of customized BitLocker recovery screen.](./images/rp-example4.png)
#### Example 5 (multiple recovery passwords)
| Custom URL | No |
|----------------------|-----------------|
| Saved to Microsoft Account | Yes |
| Saved to Azure AD | Yes |
| Saved to Active Directory | No |
| Printed | No |
| Saved to file | No |
| Creation time | **1PM** |
| Key ID | 99631A34 |
| Custom URL | No |
|----------------------|-----------------|
| Saved to Microsoft Account | No |
| Saved to Azure AD | Yes |
| Saved to Active Directory | No |
| Printed | No |
| Saved to file | No |
| Creation time | **3PM** |
| Key ID | 9DF70931 |
**Result:** The hint for the most recent key is displayed.
![Example 5 of customized BitLocker recovery screen.](./images/rp-example5.png)
## Using additional recovery information
Besides the 48-digit BitLocker recovery password, other types of recovery information are stored in Active Directory. This section describes how this additional information can be used.
### BitLocker key package
If the recovery methods discussed earlier in this document don't unlock the volume, the BitLocker Repair tool can be used to decrypt the volume at the block level. The tool uses the BitLocker key package to help recover encrypted data from severely damaged drives. The recovered data can then be used to salvage encrypted data, even after the correct recovery password has failed to unlock the damaged volume. It's recommended to still save the recovery password. A key package can't be used without the corresponding recovery password.
> [!NOTE]
> The BitLocker Repair tool `repair-bde.exe` must be used to use the BitLocker key package.
The BitLocker key package isn't saved by default. To save the package along with the recovery password in AD DS, the **Backup recovery password and key package** option must be selected in the group policy settings that control the recovery method. The key package can also be exported from a working volume. For more information on how to export key packages, see [Retrieving the BitLocker Key Package](#retrieving-the-bitlocker-key-package).
## Resetting recovery passwords
It's recommended to invalidate a recovery password after it has been provided and used. The recovery password can be invalidated when it has been provided and used or for any other valid reason.
The recovery password and be invalidated and reset in two ways:
- **Use `manage-bde.exe`**: `manage-bde.exe` can be used to remove the old recovery password and add a new recovery password. The procedure identifies the command and the syntax for this method.
- **Run a script**: A script can be run to reset the password without decrypting the volume. The sample script in the procedure illustrates this functionality. The sample script creates a new recovery password and invalidates all other passwords.
### Resetting a recovery password using `manage-bde.exe`
1. Remove the previous recovery password.
```cmd
`manage-bde.exe` -protectors -delete C: -type RecoveryPassword
```
2. Add the new recovery password.
```cmd
`manage-bde.exe` -protectors -add C: -RecoveryPassword
```
3. Get the ID of the new recovery password. From the screen, copy the ID of the recovery password.
```cmd
`manage-bde.exe` -protectors -get C: -Type RecoveryPassword
```
4. Back up the new recovery password to AD DS.
```cmd
`manage-bde.exe` -protectors -adbackup C: -id {EXAMPLE6-5507-4924-AA9E-AFB2EB003692}
```
> [!WARNING]
> The braces `{}` must be included in the ID string.
### Running the sample recovery password script to reset the recovery passwords
1. Save the following sample script in a VBScript file. For example:
`ResetPassword.vbs`.
2. At the command prompt, enter the following command::
```cmd
cscript.exe ResetPassword.vbs
```
> [!IMPORTANT]
> This sample script is configured to work only for the C volume. If necessary, customize the script to match the volume where the password reset needs to be tested.
> [!NOTE]
> To manage a remote computer, specify the remote computer name rather than the local computer name.
The following sample VBScript can be used to reset the recovery passwords:
<br>
<details>
<summary>Expand to view sample recovery password VBscript to reset the recovery passwords</summary>
```vb
' Target drive letter
strDriveLetter = "c:"
' Target computer name
' Use "." to connect to the local computer
strComputerName = "."
' --------------------------------------------------------------------------------
' Connect to the BitLocker WMI provider class
' --------------------------------------------------------------------------------
strConnectionStr = "winmgmts:" _
& "{impersonationLevel=impersonate,authenticationLevel=pktPrivacy}!\\" _
& strComputerName _
& "\root\cimv2\Security\MicrosoftVolumeEncryption"
On Error Resume Next 'handle permission errors
Set objWMIService = GetObject(strConnectionStr)
If Err.Number <> 0 Then
WScript.Echo "Failed to connect to the BitLocker interface (Error 0x" & Hex(Err.Number) & ")."
Wscript.Echo "Ensure that you are running with administrative privileges."
WScript.Quit -1
End If
On Error GoTo 0
strQuery = "Select * from Win32_EncryptableVolume where DriveLetter='" & strDriveLetter & "'"
Set colTargetVolumes = objWMIService.ExecQuery(strQuery)
If colTargetVolumes.Count = 0 Then
WScript.Echo "FAILURE: Unable to find BitLocker-capable drive " & strDriveLetter & " on computer " & strComputerName & "."
WScript.Quit -1
End If
' there should only be one volume found
For Each objFoundVolume in colTargetVolumes
set objVolume = objFoundVolume
Next
' objVolume is now our found BitLocker-capable disk volume
' --------------------------------------------------------------------------------
' Perform BitLocker WMI provider functionality
' --------------------------------------------------------------------------------
' Add a new recovery password, keeping the ID around so it doesn't get deleted later
' ----------------------------------------------------------------------------------
nRC = objVolume.ProtectKeyWithNumericalPassword("Recovery Password Refreshed By Script", , sNewKeyProtectorID)
If nRC <> 0 Then
WScript.Echo "FAILURE: ProtectKeyWithNumericalPassword failed with return code 0x" & Hex(nRC)
WScript.Quit -1
End If
' Removes the other, "stale", recovery passwords
' ----------------------------------------------------------------------------------
nKeyProtectorTypeIn = 3 ' type associated with "Numerical Password" protector
nRC = objVolume.GetKeyProtectors(nKeyProtectorTypeIn, aKeyProtectorIDs)
If nRC <> 0 Then
WScript.Echo "FAILURE: GetKeyProtectors failed with return code 0x" & Hex(nRC)
WScript.Quit -1
End If
' Delete those key protectors other than the one we just added.
For Each sKeyProtectorID In aKeyProtectorIDs
If sKeyProtectorID <> sNewKeyProtectorID Then
nRC = objVolume.DeleteKeyProtector(sKeyProtectorID)
If nRC <> 0 Then
WScript.Echo "FAILURE: DeleteKeyProtector on ID " & sKeyProtectorID & " failed with return code 0x" & Hex(nRC)
WScript.Quit -1
Else
' no output
'WScript.Echo "SUCCESS: Key protector with ID " & sKeyProtectorID & " deleted"
End If
End If
Next
WScript.Echo "A new recovery password has been added. Old passwords have been removed."
' - some advanced output (hidden)
'WScript.Echo ""
'WScript.Echo "Type ""manage-bde.exe -protectors -get " & strDriveLetter & " -type recoverypassword"" to view existing passwords."
```
</details>
## Retrieving the BitLocker key package
Two methods can be used to retrieve the key package as described in [Using Additional Recovery Information](#using-additional-recovery-information):
- **Export a previously saved key package from AD DS.** Read access is required to BitLocker recovery passwords that are stored in AD DS.
- **Export a new key package from an unlocked, BitLocker-protected volume.** Local administrator access to the working volume is required before any damage occurred to the volume.
### Running the sample key package retrieval script that exports all previously saved key packages from AD DS
The following steps and sample script exports all previously saved key packages from AD DS.
1. Save the following sample script in a VBScript file. For example: `GetBitLockerKeyPackageADDS.vbs`.
2. At the command prompt, enter a command similar to the following sample script:
```cmd
cscript.exe GetBitLockerKeyPackageADDS.vbs -?
```
The following sample script can be used to create a VBScript file to retrieve the BitLocker key package from AD DS:
<br>
<details>
<summary>Expand to view sample key package retrieval VBscript that exports all previously saved key packages from AD DS</summary>
```vb
' --------------------------------------------------------------------------------
' Usage
' --------------------------------------------------------------------------------
Sub ShowUsage
Wscript.Echo "USAGE: GetBitLockerKeyPackageADDS [Path To Save Key Package] [Optional Computer Name]"
Wscript.Echo "If no computer name is specified, the local computer is assumed."
Wscript.Echo
Wscript.Echo "Example: GetBitLockerKeyPackageADDS E:\bitlocker-ad-key-package mycomputer"
WScript.Quit
End Sub
' --------------------------------------------------------------------------------
' Parse Arguments
' --------------------------------------------------------------------------------
Set args = WScript.Arguments
Select Case args.Count
Case 1
If args(0) = "/?" Or args(0) = "-?" Then
ShowUsage
Else
strFilePath = args(0)
' Get the name of the local computer
Set objNetwork = CreateObject("WScript.Network")
strComputerName = objNetwork.ComputerName
End If
Case 2
If args(0) = "/?" Or args(0) = "-?" Then
ShowUsage
Else
strFilePath = args(0)
strComputerName = args(1)
End If
Case Else
ShowUsage
End Select
' --------------------------------------------------------------------------------
' Get path to Active Directory computer object associated with the computer name
' --------------------------------------------------------------------------------
Function GetStrPathToComputer(strComputerName)
' Uses the global catalog to find the computer in the forest
' Search also includes deleted computers in the tombstone
Set objRootLDAP = GetObject("LDAP://rootDSE")
namingContext = objRootLDAP.Get("defaultNamingContext") ' e.g. string dc=fabrikam,dc=com
strBase = "<GC://" & namingContext & ">"
Set objConnection = CreateObject("ADODB.Connection")
Set objCommand = CreateObject("ADODB.Command")
objConnection.Provider = "ADsDSOOBject"
objConnection.Open "Active Directory Provider"
Set objCommand.ActiveConnection = objConnection
strFilter = "(&(objectCategory=Computer)(cn=" & strComputerName & "))"
strQuery = strBase & ";" & strFilter & ";distinguishedName;subtree"
objCommand.CommandText = strQuery
objCommand.Properties("Page Size") = 100
objCommand.Properties("Timeout") = 100
objCommand.Properties("Cache Results") = False
' Enumerate all objects found.
Set objRecordSet = objCommand.Execute
If objRecordSet.EOF Then
WScript.echo "The computer name '" & strComputerName & "' cannot be found."
WScript.Quit 1
End If
' Found object matching name
Do Until objRecordSet.EOF
dnFound = objRecordSet.Fields("distinguishedName")
GetStrPathToComputer = "LDAP://" & dnFound
objRecordSet.MoveNext
Loop
' Clean up.
Set objConnection = Nothing
Set objCommand = Nothing
Set objRecordSet = Nothing
End Function
' --------------------------------------------------------------------------------
' Securely access the Active Directory computer object using Kerberos
' --------------------------------------------------------------------------------
Set objDSO = GetObject("LDAP:")
strPathToComputer = GetStrPathToComputer(strComputerName)
WScript.Echo "Accessing object: " + strPathToComputer
Const ADS_SECURE_AUTHENTICATION = 1
Const ADS_USE_SEALING = 64 '0x40
Const ADS_USE_SIGNING = 128 '0x80
' --------------------------------------------------------------------------------
' Get all BitLocker recovery information from the Active Directory computer object
' --------------------------------------------------------------------------------
' Get all the recovery information child objects of the computer object
Set objFveInfos = objDSO.OpenDSObject(strPathToComputer, vbNullString, vbNullString, _
ADS_SECURE_AUTHENTICATION + ADS_USE_SEALING + ADS_USE_SIGNING)
objFveInfos.Filter = Array("msFVE-RecoveryInformation")
' Iterate through each recovery information object and saves any existing key packages
nCount = 1
strFilePathCurrent = strFilePath & nCount
For Each objFveInfo in objFveInfos
strName = objFveInfo.Get("name")
strRecoveryPassword = objFveInfo.Get("msFVE-RecoveryPassword")
strKeyPackage = objFveInfo.Get("msFVE-KeyPackage")
WScript.echo
WScript.echo "Recovery Object Name: " + strName
WScript.echo "Recovery Password: " + strRecoveryPassword
' Validate file path
Set fso = CreateObject("Scripting.FileSystemObject")
If (fso.FileExists(strFilePathCurrent)) Then
WScript.Echo "The file " & strFilePathCurrent & " already exists. Please use a different path."
WScript.Quit -1
End If
' Save binary data to the file
SaveBinaryDataText strFilePathCurrent, strKeyPackage
WScript.echo "Related key package successfully saved to " + strFilePathCurrent
' Update next file path using base name
nCount = nCount + 1
strFilePathCurrent = strFilePath & nCount
Next
'----------------------------------------------------------------------------------------
' Utility functions to save binary data
'----------------------------------------------------------------------------------------
Function SaveBinaryDataText(FileName, ByteArray)
'Create FileSystemObject object
Dim FS: Set FS = CreateObject("Scripting.FileSystemObject")
'Create text stream object
Dim TextStream
Set TextStream = FS.CreateTextFile(FileName)
'Convert binary data To text And write them To the file
TextStream.Write BinaryToString(ByteArray)
End Function
Function BinaryToString(Binary)
Dim I, S
For I = 1 To LenB(Binary)
S = S & Chr(AscB(MidB(Binary, I, 1)))
Next
BinaryToString = S
End Function
WScript.Quit
```
</details>
### Running the sample key package retrieval script that exports a new key package from an unlocked, encrypted volume
The following steps and sample script exports a new key package from an unlocked, encrypted volume.
1. Save the following sample script in a VBScript file. For example: `GetBitLockerKeyPackage.vbs`
2. Open an administrator command prompt, and then enter a command similar to the following sample script:
```cmd
cscript.exe GetBitLockerKeyPackage.vbs -?
```
<br>
<details>
<summary>Expand to view sample VBscript that exports a new key package from an unlocked, encrypted volume</summary>
```vb
' --------------------------------------------------------------------------------
' Usage
' --------------------------------------------------------------------------------
Sub ShowUsage
Wscript.Echo "USAGE: GetBitLockerKeyPackage [VolumeLetter/DriveLetter:] [Path To Save Key Package]"
Wscript.Echo
Wscript.Echo "Example: GetBitLockerKeyPackage C: E:\bitlocker-backup-key-package"
WScript.Quit
End Sub
' --------------------------------------------------------------------------------
' Parse Arguments
' --------------------------------------------------------------------------------
Set args = WScript.Arguments
Select Case args.Count
Case 2
If args(0) = "/?" Or args(0) = "-?" Then
ShowUsage
Else
strDriveLetter = args(0)
strFilePath = args(1)
End If
Case Else
ShowUsage
End Select
' --------------------------------------------------------------------------------
' Other Inputs
' --------------------------------------------------------------------------------
' Target computer name
' Use "." to connect to the local computer
strComputerName = "."
' Default key protector ID to use. Specify "" to let the script choose.
strDefaultKeyProtectorID = ""
' strDefaultKeyProtectorID = "{001298E0-870E-4BA0-A2FF-FC74758D5720}" ' sample
' --------------------------------------------------------------------------------
' Connect to the BitLocker WMI provider class
' --------------------------------------------------------------------------------
strConnectionStr = "winmgmts:" _
& "{impersonationLevel=impersonate,authenticationLevel=pktPrivacy}!\\" _
& strComputerName _
& "\root\cimv2\Security\MicrosoftVolumeEncryption"
On Error Resume Next 'handle permission errors
Set objWMIService = GetObject(strConnectionStr)
If Err.Number <> 0 Then
WScript.Echo "Failed to connect to the BitLocker interface (Error 0x" & Hex(Err.Number) & ")."
Wscript.Echo "Ensure that you are running with administrative privileges."
WScript.Quit -1
End If
On Error GoTo 0
strQuery = "Select * from Win32_EncryptableVolume where DriveLetter='" & strDriveLetter & "'"
Set colTargetVolumes = objWMIService.ExecQuery(strQuery)
If colTargetVolumes.Count = 0 Then
WScript.Echo "FAILURE: Unable to find BitLocker-capable drive " & strDriveLetter & " on computer " & strComputerName & "."
WScript.Quit -1
End If
' there should only be one volume found
For Each objFoundVolume in colTargetVolumes
set objVolume = objFoundVolume
Next
' objVolume is now our found BitLocker-capable disk volume
' --------------------------------------------------------------------------------
' Perform BitLocker WMI provider functionality
' --------------------------------------------------------------------------------
' Collect all possible valid key protector ID's that can be used to get the package
' ----------------------------------------------------------------------------------
nNumericalKeyProtectorType = 3 ' type associated with "Numerical Password" protector
nRC = objVolume.GetKeyProtectors(nNumericalKeyProtectorType, aNumericalKeyProtectorIDs)
If nRC <> 0 Then
WScript.Echo "FAILURE: GetKeyProtectors failed with return code 0x" & Hex(nRC)
WScript.Quit -1
End If
nExternalKeyProtectorType = 2 ' type associated with "External Key" protector
nRC = objVolume.GetKeyProtectors(nExternalKeyProtectorType, aExternalKeyProtectorIDs)
If nRC <> 0 Then
WScript.Echo "FAILURE: GetKeyProtectors failed with return code 0x" & Hex(nRC)
WScript.Quit -1
End If
' Get first key protector of the type "Numerical Password" or "External Key", if any
' ----------------------------------------------------------------------------------
if strDefaultKeyProtectorID = "" Then
' Save first numerical password, if exists
If UBound(aNumericalKeyProtectorIDs) <> -1 Then
strDefaultKeyProtectorID = aNumericalKeyProtectorIDs(0)
End If
' No numerical passwords exist, save the first external key
If strDefaultKeyProtectorID = "" and UBound(aExternalKeyProtectorIDs) <> -1 Then
strDefaultKeyProtectorID = aExternalKeyProtectorIDs(0)
End If
' Fail case: no recovery key protectors exist.
If strDefaultKeyProtectorID = "" Then
WScript.Echo "FAILURE: Cannot create backup key package because no recovery passwords or recovery keys exist. Check that BitLocker protection is on for this drive."
WScript.Echo "For help adding recovery passwords or recovery keys, enter ""manage-bde.exe -protectors -add -?""."
WScript.Quit -1
End If
End If
' Get some information about the chosen key protector ID
' ----------------------------------------------------------------------------------
' is the type valid?
nRC = objVolume.GetKeyProtectorType(strDefaultKeyProtectorID, nDefaultKeyProtectorType)
If Hex(nRC) = "80070057" Then
WScript.Echo "The key protector ID " & strDefaultKeyProtectorID & " is not valid."
WScript.Echo "This ID value may have been provided by the script writer."
ElseIf nRC <> 0 Then
WScript.Echo "FAILURE: GetKeyProtectorType failed with return code 0x" & Hex(nRC)
WScript.Quit -1
End If
' what's a string that can be used to describe it?
strDefaultKeyProtectorType = ""
Select Case nDefaultKeyProtectorType
Case nNumericalKeyProtectorType
strDefaultKeyProtectorType = "recovery password"
Case nExternalKeyProtectorType
strDefaultKeyProtectorType = "recovery key"
Case Else
WScript.Echo "The key protector ID " & strDefaultKeyProtectorID & " does not refer to a valid recovery password or recovery key."
WScript.Echo "This ID value may have been provided by the script writer."
End Select
' Save the backup key package using the chosen key protector ID
' ----------------------------------------------------------------------------------
nRC = objVolume.GetKeyPackage(strDefaultKeyProtectorID, oKeyPackage)
If nRC <> 0 Then
WScript.Echo "FAILURE: GetKeyPackage failed with return code 0x" & Hex(nRC)
WScript.Quit -1
End If
' Validate file path
Set fso = CreateObject("Scripting.FileSystemObject")
If (fso.FileExists(strFilePath)) Then
WScript.Echo "The file " & strFilePath & " already exists. Please use a different path."
WScript.Quit -1
End If
Dim oKeyPackageByte, bKeyPackage
For Each oKeyPackageByte in oKeyPackage
'WScript.echo "key package byte: " & oKeyPackageByte
bKeyPackage = bKeyPackage & ChrB(oKeyPackageByte)
Next
' Save binary data to the file
SaveBinaryDataText strFilePath, bKeyPackage
' Display helpful information
' ----------------------------------------------------------------------------------
WScript.Echo "The backup key package has been saved to " & strFilePath & "."
WScript.Echo "IMPORTANT: To use this key package, the " & strDefaultKeyProtectorType & " must also be saved."
' Display the recovery password or a note about saving the recovery key file
If nDefaultKeyProtectorType = nNumericalKeyProtectorType Then
nRC = objVolume.GetKeyProtectorNumericalPassword(strDefaultKeyProtectorID, sNumericalPassword)
If nRC <> 0 Then
WScript.Echo "FAILURE: GetKeyProtectorNumericalPassword failed with return code 0x" & Hex(nRC)
WScript.Quit -1
End If
WScript.Echo "Save this recovery password: " & sNumericalPassword
ElseIf nDefaultKeyProtectorType = nExternalKeyProtectorType Then
WScript.Echo "The saved key file is named " & strDefaultKeyProtectorID & ".BEK"
WScript.Echo "For help re-saving this external key file, enter ""manage-bde.exe -protectors -get -?"""
End If
'----------------------------------------------------------------------------------------
' Utility functions to save binary data
'----------------------------------------------------------------------------------------
Function SaveBinaryDataText(FileName, ByteArray)
'Create FileSystemObject object
Dim FS: Set FS = CreateObject("Scripting.FileSystemObject")
'Create text stream object
Dim TextStream
Set TextStream = FS.CreateTextFile(FileName)
'Convert binary data To text And write them To the file
TextStream.Write BinaryToString(ByteArray)
End Function
Function BinaryToString(Binary)
Dim I, S
For I = 1 To LenB(Binary)
S = S & Chr(AscB(MidB(Binary, I, 1)))
Next
BinaryToString = S
End Function
```
</details>
## Related articles
- [BitLocker overview](bitlocker-overview.md)

41
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@ -0,0 +1,41 @@
### YamlMime:FAQ
metadata:
title: BitLocker Security FAQ
description: Learn more about how BitLocker security works. Browse frequently asked questions, such as, "What form of encryption does BitLocker use?"
ms.prod: windows-client
ms.technology: itpro-security
author: frankroj
ms.author: frankroj
manager: aaroncz
audience: ITPro
ms.topic: faq
ms.date: 11/08/2022
ms.custom: bitlocker
title: BitLocker Security FAQ
summary: |
sections:
- name: Ignored
questions:
- question: |
What form of encryption does BitLocker use? Is it configurable?
answer: |
BitLocker uses Advanced Encryption Standard (AES) as its encryption algorithm with configurable key lengths of 128 bits or 256 bits. The default encryption setting is AES-128, but the options are configurable by using Group Policy.
- question: |
What is the best practice for using BitLocker on an operating system drive?
answer: |
The recommended practice for BitLocker configuration on an operating system drive is to implement BitLocker on a computer with a TPM version 1.2 or higher, and a Trusted Computing Group (TCG)-compliant BIOS or UEFI firmware implementation, along with a PIN. By requiring a PIN that was set by the user in addition to the TPM validation, a malicious user that has physical access to the computer can't start the computer.
- question: |
What are the implications of using the sleep or hibernate power management options?
answer: |
BitLocker on operating system drives in its basic configuration (with a TPM but without other startup authentication) provides extra security for the hibernate mode. However, BitLocker provides greater security when it's configured to use another startup authentication factor (TPM+PIN, TPM+USB, or TPM+PIN+USB) with the hibernate mode. This method is more secure because returning from hibernation requires authentication. In sleep mode, the computer is vulnerable to direct memory access attacks, since unprotected data remains in RAM. Therefore, for improved security, it's recommended to disable sleep mode and to use TPM+PIN for the authentication method. Startup authentication can be configured by using [Group Policy](./bitlocker-group-policy-settings.md) or Mobile Device Management with the [BitLocker CSP](/windows/client-management/mdm/bitlocker-csp).
- question: |
What are the advantages of a TPM?
answer: |
Most operating systems use a shared memory space and rely on the operating system to manage physical memory. A TPM is a hardware component that uses its own internal firmware and logic circuits for processing instructions, thus shielding it from external software vulnerabilities. Attacking the TPM requires physical access to the computer. Additionally, the tools and skills necessary to attack hardware are often more expensive, and usually aren't as available as the ones used to attack software. And because each TPM is unique to the computer that contains it, attacking multiple TPM computers would be difficult and time-consuming.
> [!NOTE]
> Configuring BitLocker with an additional factor of authentication provides even more protection against TPM hardware attacks.

31
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@ -0,0 +1,31 @@
### YamlMime:FAQ
metadata:
title: BitLocker To Go FAQ
description: "Learn more about BitLocker To Go"
ms.prod: windows-client
ms.technology: itpro-security
ms.author: frankroj
author: frankroj
manager: aaroncz
audience: ITPro
ms.topic: faq
ms.date: 11/08/2022
ms.custom: bitlocker
title: BitLocker To Go FAQ
summary: |
sections:
- name: Ignored
questions:
- question: What is BitLocker To Go?
answer: |
BitLocker To Go is BitLocker Drive Encryption on removable data drives. This feature includes the encryption of:
- USB flash drives
- SD cards
- External hard disk drives
- Other drives that are formatted by using the NTFS, FAT16, FAT32, or exFAT file system.
Drive partitioning must meet the [BitLocker Drive Encryption Partitioning Requirements](/windows-hardware/manufacture/desktop/bitlocker-drive-encryption#bitlocker-drive-encryption-partitioning-requirements).
As with BitLocker, drives that are encrypted by BitLocker To Go can be opened by using a password or smart card on another computer. In Control Panel, use **BitLocker Drive Encryption**.

46
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@ -0,0 +1,46 @@
### YamlMime:FAQ
metadata:
title: BitLocker Upgrading FAQ
description: Learn more about upgrading systems that have BitLocker enabled. Find frequently asked questions, such as, "Can I upgrade to Windows 10 with BitLocker enabled?"
ms.prod: windows-client
ms.technology: itpro-security
author: frankroj
ms.author: frankroj
manager: aaroncz
ms.topic: faq
ms.date: 11/08/2022
ms.reviewer:
ms.custom: bitlocker
title: BitLocker Upgrading FAQ
summary: |
sections:
- name: Ignored
questions:
- question: |
Can I upgrade to Windows 10 with BitLocker enabled?
answer: |
Yes.
- question: |
What is the difference between suspending and decrypting BitLocker?
answer: |
**Decrypt** completely removes BitLocker protection and fully decrypts the drive.
**Suspend** keeps the data encrypted but encrypts the BitLocker volume master key with a clear key. The clear key is a cryptographic key stored unencrypted and unprotected on the disk drive. By storing this key unencrypted, the **Suspend** option allows for changes or upgrades to the computer without the time and cost of decrypting and re-encrypting the entire drive. After the changes are made and BitLocker is again enabled, BitLocker will reseal the encryption key to the new values of the measured components that changed as a part of the upgrade, the volume master key is changed, the protectors are updated to match and the clear key is erased.
- question: |
Do I have to suspend BitLocker protection to download and install system updates and upgrades?
answer: |
No user action is required for BitLocker in order to apply updates from Microsoft, including [Windows quality updates and feature updates](/windows/deployment/update/waas-quick-start).
Users need to suspend BitLocker for Non-Microsoft software updates, such as:
- Some TPM firmware updates if these updates clear the TPM outside of the Windows API. Not every TPM firmware update will clear the TPM. Users don't have to suspend BitLocker if the TPM firmware update uses Windows API to clear the TPM because in this case, BitLocker will be automatically suspended. It's recommended that users test their TPM firmware updates if they don't want to suspend BitLocker protection.
- Non-Microsoft application updates that modify the UEFI\BIOS configuration.
- Manual or third-party updates to secure boot databases (only if BitLocker uses Secure Boot for integrity validation).
- Updates to UEFI\BIOS firmware, installation of additional UEFI drivers, or UEFI applications without using the Windows update mechanism (only if BitLocker doesn't use Secure Boot for integrity validation during updates).
- BitLocker can be checked if it uses Secure Boot for integrity validation with the command line `manage-bde.exe -protectors -get C:`. If Secure Boot for integrity validation is being used, it will be report **Uses Secure Boot for integrity validation**.
> [!NOTE]
> If BitLocker has been suspended, BitLocker protection can be resumed after the upgrade or update has been installed. Upon resuming protection, BitLocker will reseal the encryption key to the new values of the measured components that changed as a part of the upgrade or update. If these types of upgrades or updates are applied without suspending BitLocker, the computer will enter recovery mode when restarting and will require a recovery key or password to access the computer.

239
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@ -0,0 +1,239 @@
---
title: BitLocker Use BitLocker Drive Encryption Tools to manage BitLocker
description: This article for the IT professional describes how to use tools to manage BitLocker.
ms.collection:
- highpri
- tier1
ms.topic: conceptual
ms.date: 11/08/2022
---
# BitLocker: Use BitLocker Drive Encryption Tools to manage BitLocker
This article for the IT professional describes how to use tools to manage BitLocker.
BitLocker Drive Encryption Tools include the command-line tools manage-bde and repair-bde and the BitLocker cmdlets for Windows PowerShell.
Both manage-bde and the BitLocker cmdlets can be used to perform any task that can be accomplished through the BitLocker control panel and are appropriate to use for automated deployments and other scripting scenarios.
Repair-bde is a special circumstance tool that is provided for disaster recovery scenarios in which a BitLocker protected drive can't be unlocked normally or using the recovery console.
1. [Manage-bde](#manage-bde)
2. [Repair-bde](#repair-bde)
3. [BitLocker cmdlets for Windows PowerShell](#bitlocker-cmdlets-for-windows-powershell)
## Manage-bde
Manage-bde is a command-line tool that can be used for scripting BitLocker operations. Manage-bde offers additional options not displayed in the BitLocker control panel. For a complete list of the `manage-bde.exe` options, see the [Manage-bde](/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/ff829849(v=ws.11)) command-line reference.
Manage-bde includes fewer default settings and requires greater customization for configuring BitLocker. For example, using just the `manage-bde.exe -on` command on a data volume will fully encrypt the volume without any authenticating protectors. A volume encrypted in this manner still requires user interaction to turn on BitLocker protection, even though the command successfully completed because an authentication method needs to be added to the volume for it to be fully protected. The following sections provide examples of common usage scenarios for manage-bde.
### Using manage-bde with operating system volumes
Listed below are examples of basic valid commands for operating system volumes. In general, using only the `manage-bde.exe -on <drive letter>` command will encrypt the operating system volume with a TPM-only protector and no recovery key. However, many environments require more secure protectors such as passwords or PIN and expect information recovery with a recovery key. It's recommended to add at least one primary protector plus a recovery protector to an operating system volume.
A good practice when using `manage-bde.exe` is to determine the volume status on the target system. Use the following command to determine volume status:
```cmd
manage-bde.exe -status
```
This command returns the volumes on the target, current encryption status, encryption method, and volume type (operating system or data) for each volume:
![Using manage-bde to check encryption status.](images/manage-bde-status.png)
The following example illustrates enabling BitLocker on a computer without a TPM chip. Before beginning the encryption process, the startup key needed for BitLocker must be created and saved to a USB drive. When BitLocker is enabled for the operating system volume, BitLocker will need to access the USB flash drive to obtain the encryption key. In this example, the drive letter E represents the USB drive. Once the commands are run, it will prompt to reboot the computer to complete the encryption process.
```cmd
manage-bde.exe -protectors -add C: -startupkey E:
manage-bde.exe -on C:
```
> [!NOTE]
> After the encryption is completed, the USB startup key must be inserted before the operating system can be started.
An alternative to the startup key protector on non-TPM hardware is to use a password and an **ADaccountorgroup** protector to protect the operating system volume. In this scenario, the protectors are added first. To add the protectors, enter the following command:
```cmd
manage-bde.exe -protectors -add C: -pw -sid <user or group>
```
The above command will require the password protector to be entered and confirmed before adding them to the volume. With the protectors enabled on the volume, BitLocker can then be turned on.
On computers with a TPM, it's possible to encrypt the operating system volume without defining any protectors using `manage-bde.exe`. To enable BitLocker on a computer with a TPM without defining any protectors, enter the following command:
```cmd
manage-bde.exe -on C:
```
The above command encrypts the drive using the TPM as the default protector. If verify if a TPM protector is available, the list of protectors available for a volume can be listed by running the following command:
```cmd
manage-bde.exe -protectors -get <volume>
```
### Using manage-bde with data volumes
Data volumes use the same syntax for encryption as operating system volumes but they don't require protectors for the operation to complete. Encrypting data volumes can be done using the base command:
`manage-bde.exe -on <drive letter>`
or additional protectors can be added to the volume first. It's recommended to add at least one primary protector plus a recovery protector to a data volume.
A common protector for a data volume is the password protector. In the example below, a password protector is added to the volume and then BitLocker is turned on.
```cmd
manage-bde.exe -protectors -add -pw C:
manage-bde.exe -on C:
```
## Repair-bde
Hard disk areas on which BitLocker stores critical information could be damaged, for example, when a hard disk fails or if Windows exits unexpectedly.
The BitLocker Repair Tool (Repair-bde) can be used to access encrypted data on a severely damaged hard disk if the drive was encrypted with BitLocker. Repair-bde can reconstruct critical parts of the drive and salvage recoverable data as long as a valid recovery password or recovery key is used to decrypt the data. If the BitLocker metadata data on the drive has become corrupt, the backup key package in addition to the recovery password or recovery key must be supplied. This key package is backed up in Active Directory Domain Services (AD DS) if the default settings for AD DS backup are used. With this key package and either the recovery password or recovery key, portions of a corrupted BitLocker-protected drive can be decrypted. Each key package will work only for a drive that has the corresponding drive identifier. The BitLocker Recovery Password Viewer can be used to obtain this key package from AD DS.
> [!TIP]
> If recovery information is not being backed up to AD DS or if key packages need to be saved in an alternative way, the command:
>
> `manage-bde.exe -KeyPackage`
>
> can be used to generate a key package for a volume.
The Repair-bde command-line tool is intended for use when the operating system doesn't start or when the BitLocker Recovery Console can't be started. Use Repair-bde if the following conditions are true:
- The drive has been encrypted using BitLocker Drive Encryption.
- Windows doesn't start, or the BitLocker recovery console can't be started.
- There isn't a backup copy of the data that is contained on the encrypted drive.
> [!NOTE]
> Damage to the drive may not be related to BitLocker. Therefore, it is recommended to try other tools to help diagnose and resolve the problem with the drive before using the BitLocker Repair Tool. The Windows Recovery Environment (Windows RE) provides additional options to repair computers.
The following limitations exist for Repair-bde:
- The Repair-bde command-line tool can't repair a drive that failed during the encryption or decryption process.
- The Repair-bde command-line tool assumes that if the drive has any encryption, then the drive has been fully encrypted.
For more information about using repair-bde, see [Repair-bde](/previous-versions/windows/it-pro/windows-server-2012-R2-and-2012/ff829851(v=ws.11)).
## BitLocker cmdlets for Windows PowerShell
Windows PowerShell cmdlets provide a new way for administrators to use when working with BitLocker. Using Windows PowerShell's scripting capabilities, administrators can integrate BitLocker options into existing scripts with ease. The list below displays the available BitLocker cmdlets.
|Name|Parameters|
|--- |--- |
|**Add-BitLockerKeyProtector**|<li>ADAccountOrGroup<li>ADAccountOrGroupProtector<li>Confirm<li>MountPoint<li>Password<li>PasswordProtector<li>Pin<li>RecoveryKeyPath<li>RecoveryKeyProtector<li>RecoveryPassword<li>RecoveryPasswordProtector<li>Service<li>StartupKeyPath<li>StartupKeyProtector<li>TpmAndPinAndStartupKeyProtector<li>TpmAndPinProtector<li>TpmAndStartupKeyProtector<li>TpmProtector<li>WhatIf|
|**Backup-BitLockerKeyProtector**|<li>Confirm<li>KeyProtectorId<li>MountPoint<li>WhatIf|
|**Disable-BitLocker**|<li>Confirm<li>MountPoint<li>WhatIf|
|**Disable-BitLockerAutoUnlock**|<li>Confirm<li>MountPoint<li>WhatIf|
|**Enable-BitLocker**|<li>AdAccountOrGroup<li>AdAccountOrGroupProtector<li>Confirm<li>EncryptionMethod<li>HardwareEncryption<li>Password<li>PasswordProtector<li>Pin<li>RecoveryKeyPath<li>RecoveryKeyProtector<li>RecoveryPassword<li>RecoveryPasswordProtector<li>Service<li>SkipHardwareTest<li>StartupKeyPath<li>StartupKeyProtector<li>TpmAndPinAndStartupKeyProtector<li>TpmAndPinProtector<li>TpmAndStartupKeyProtector<li>TpmProtector<li>UsedSpaceOnly<li>WhatIf|
|**Enable-BitLockerAutoUnlock**|<li>Confirm<li>MountPoint<li>WhatIf|
|**Get-BitLockerVolume**|<li>MountPoint|
|**Lock-BitLocker**|<li>Confirm<li>ForceDismount<li>MountPoint<li>WhatIf|
|**Remove-BitLockerKeyProtector**|<li>Confirm<li>KeyProtectorId<li>MountPoint<li>WhatIf|
|**Resume-BitLocker**|<li>Confirm<li>MountPoint<li>WhatIf|
|**Suspend-BitLocker**|<li>Confirm<li>MountPoint<li>RebootCount<li>WhatIf|
|**Unlock-BitLocker**|<li>AdAccountOrGroup<li>Confirm<li>MountPoint<li>Password<li>RecoveryKeyPath<li>RecoveryPassword<li>RecoveryPassword<li>WhatIf|
Similar to manage-bde, the Windows PowerShell cmdlets allow configuration beyond the options offered in the control panel. As with manage-bde, users need to consider the specific needs of the volume they're encrypting prior to running Windows PowerShell cmdlets.
A good initial step is to determine the current state of the volume(s) on the computer. Determining the current state of the volume(s) can be done using the `Get-BitLockerVolume` cmdlet.
The `Get-BitLockerVolume` cmdlet output gives information on the volume type, protectors, protection status, and other details.
> [!TIP]
> Occasionally, all protectors may not be shown when using `Get-BitLockerVolume` due to lack of space in the output display. If all of the protectors for a volume are not seen, use the Windows PowerShell pipe command (|) to format a full listing of the protectors:
>
> `Get-BitLockerVolume C: | fl`
To remove the existing protectors prior to provisioning BitLocker on the volume, use the `Remove-BitLockerKeyProtector` cmdlet. Running this cmdlet requires the GUID associated with the protector to be removed.
A simple script can pipe the values of each Get-BitLockerVolume return out to another variable as seen below:
```powershell
$vol = Get-BitLockerVolume
$keyprotectors = $vol.KeyProtector
```
By using this script, the information in the $keyprotectors variable can be displayed to determine the GUID for each protector.
By using this information, the key protector for a specific volume can be removed using the command:
```powershell
Remove-BitLockerKeyProtector <volume>: -KeyProtectorID "{GUID}"
```
> [!NOTE]
> The BitLocker cmdlet requires the key protector GUID enclosed in quotation marks to execute. Ensure the entire GUID, with braces, is included in the command.
### Using the BitLocker Windows PowerShell cmdlets with operating system volumes
Using the BitLocker Windows PowerShell cmdlets is similar to working with the manage-bde tool for encrypting operating system volumes. Windows PowerShell offers users flexibility. For example, users can add the desired protector as part command for encrypting the volume. Below are examples of common user scenarios and steps to accomplish them in BitLocker Windows PowerShell.
The following example shows how to enable BitLocker on an operating system drive using only the TPM protector:
```powershell
Enable-BitLocker C:
```
In the example below, adds one additional protector, the StartupKey protector and chooses to skip the BitLocker hardware test. In this example, encryption starts immediately without the need for a reboot.
```powershell
Enable-BitLocker C: -StartupKeyProtector -StartupKeyPath <path> -SkipHardwareTest
```
### Using the BitLocker Windows PowerShell cmdlets with data volumes
Data volume encryption using Windows PowerShell is the same as for operating system volumes. Add the desired protectors prior to encrypting the volume. The following example adds a password protector to the E: volume using the variable $pw as the password. The $pw variable is held as a
SecureString value to store the user-defined password.
```powershell
$pw = Read-Host -AsSecureString
<user inputs password>
Enable-BitLockerKeyProtector E: -PasswordProtector -Password $pw
```
### Using an AD Account or Group protector in Windows PowerShell
The **ADAccountOrGroup** protector, introduced in Windows 8 and Windows Server 2012, is an Active Directory SID-based protector. This protector can be added to both operating system and data volumes, although it doesn't unlock operating system volumes in the pre-boot environment. The protector requires the SID for the domain account or group to link with the protector. BitLocker can protect a cluster-aware disk by adding a SID-based protector for the Cluster Name Object (CNO) that lets the disk properly fail over to and become unlocked by any member computer of the cluster.
> [!WARNING]
> The **ADAccountOrGroup** protector requires the use of an additional protector for use (such as TPM, PIN, or recovery key) when used on operating system volumes
To add an **ADAccountOrGroup** protector to a volume, use either the actual domain SID or the group name preceded by the domain and a backslash. In the example below, the CONTOSO\\Administrator account is added as a protector to the data volume G.
```powershell
Enable-BitLocker G: -AdAccountOrGroupProtector -AdAccountOrGroup CONTOSO\Administrator
```
For users who wish to use the SID for the account or group, the first step is to determine the SID associated with the account. To get the specific SID for a user account in Windows PowerShell, use the following command:
> [!NOTE]
> Use of this command requires the RSAT-AD-PowerShell feature.
```powershell
get-aduser -filter {samaccountname -eq "administrator"}
```
> [!TIP]
> In addition to the PowerShell command above, information about the locally logged on user and group membership can be found using: WHOAMI /ALL. This doesn't require the use of additional features.
The following example adds an **ADAccountOrGroup** protector to the previously encrypted operating system volume using the SID of the account:
```powershell
Add-BitLockerKeyProtector C: -ADAccountOrGroupProtector -ADAccountOrGroup S-1-5-21-3651336348-8937238915-291003330-500
```
> [!NOTE]
> Active Directory-based protectors are normally used to unlock Failover Cluster enabled volumes.
## Related articles
- [BitLocker overview](bitlocker-overview.md)
- [BitLocker frequently asked questions (FAQ)](bitlocker-frequently-asked-questions.yml)
- [Prepare your organization for BitLocker: Planning and policies](prepare-your-organization-for-bitlocker-planning-and-policies.md)
- [BitLocker: How to enable Network Unlock](bitlocker-how-to-enable-network-unlock.md)
- [BitLocker: How to deploy on Windows Server 2012](bitlocker-how-to-deploy-on-windows-server.md)

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---
title: BitLocker Use BitLocker Recovery Password Viewer
description: This article for the IT professional describes how to use the BitLocker Recovery Password Viewer.
ms.collection:
- highpri
- tier1
ms.topic: conceptual
ms.date: 11/08/2022
---
# BitLocker: Use BitLocker Recovery Password Viewer
**Applies to:**
- Windows 10
- Windows 11
- Windows Server 2016 and above
This article describes how to use the BitLocker Recovery Password Viewer.
The BitLocker Recovery Password Viewer tool is an optional tool included with the Remote Server Administration Tools (RSAT). It lets BitLocker recovery passwords that are stored in Active Directory Domain Services (AD DS) be located and viewed. This tool can be used to help recover data that is stored on a drive that has been encrypted by using BitLocker. The BitLocker Active Directory Recovery Password Viewer tool is an extension for the Active Directory Users and Computers Microsoft Management Console (MMC) snap-in. Using this tool, a computer object's **Properties** dialog box can be examined to view the corresponding BitLocker recovery passwords.
Additionally a domain container can be searched for BitLocker recovery password across all the domains in the Active Directory forest via a right-click. Passwords can also be searched by password identifier (ID).
## Before starting
To complete the procedures in this scenario, the following requirements must be met:
- Domain administrator credentials.
- Test computers must be joined to the domain.
- On the domain-joined test computers, BitLocker must have been turned on.
The following procedures describe the most common tasks performed by using the BitLocker Recovery Password Viewer.
### To view the recovery passwords for a computer
1. In **Active Directory Users and Computers**, locate and then select the container in which the computer is located.
2. Right-click the computer object, and then select **Properties**.
3. In the **Properties** dialog box, select the **BitLocker Recovery** tab to view the BitLocker recovery passwords that are associated with the computer.
### To copy the recovery passwords for a computer
1. Follow the steps in the previous procedure to view the BitLocker recovery passwords.
2. On the **BitLocker Recovery** tab of the **Properties** dialog box, right-click the BitLocker recovery password that needs to be copied, and then select **Copy Details**.
3. Press CTRL+V to paste the copied text to a destination location, such as a text file or spreadsheet.
### To locate a recovery password by using a password ID
1. In Active Directory Users and Computers, right-click the domain container, and then select **Find BitLocker Recovery Password**.
2. In the **Find BitLocker Recovery Password** dialog box, type the first eight characters of the recovery password in the **Password ID (first 8 characters)** box, and then select **Search**.
By completing the procedures in this scenario, the recovery passwords for a computer have been viewed and copied and a password ID was used to locate a recovery password.
## Related articles
- [BitLocker Overview](bitlocker-overview.md)
- [BitLocker frequently asked questions (FAQ)](bitlocker-frequently-asked-questions.yml)
- [Prepare your organization for BitLocker: Planning and policies](prepare-your-organization-for-bitlocker-planning-and-policies.md)
- [BitLocker: How to deploy on Windows Server 2012](bitlocker-how-to-deploy-on-windows-server.md)
- [BitLocker: Use BitLocker Drive Encryption Tools to manage BitLocker](bitlocker-use-bitlocker-drive-encryption-tools-to-manage-bitlocker.md)

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### YamlMime:FAQ
metadata:
title: Using BitLocker with other programs FAQ
description: Learn how to integrate BitLocker with other software on a device.
ms.prod: windows-client
ms.technology: itpro-security
author: frankroj
ms.author: frankroj
manager: aaroncz
ms.topic: faq
ms.date: 11/08/2022
title: Using BitLocker with other programs FAQ
summary: |
**Applies to:**
- Windows 10 and later
- Windows Server 2016 and later
sections:
- name: Ignored
questions:
- question: |
Can I use EFS with BitLocker?
answer: |
Yes, Encrypting File System (EFS) can be used to encrypt files on a BitLocker-protected drive. BitLocker helps protect the entire operating system drive against offline attacks, whereas EFS can provide additional user-based file level encryption for security separation between multiple users of the same computer. EFS can also be used in Windows to encrypt files on other drives that aren't encrypted by BitLocker. The root secrets of EFS are stored by default on the operating system drive; therefore, if BitLocker is enabled for the operating system drive, data that is encrypted by EFS on other drives is also indirectly protected by BitLocker.
- question: |
Can I run a kernel debugger with BitLocker?
answer: |
Yes. However, the debugger should be turned on before enabling BitLocker. Turning on the debugger ensures that the correct measurements are calculated when sealing to the TPM, allowing the computer to start properly. If debugging needs to be turned on or off when using BitLocker, be sure to suspend BitLocker first to avoid putting the computer into recovery mode.
- question: |
How does BitLocker handle memory dumps?
answer: |
BitLocker has a storage driver stack that ensures memory dumps are encrypted when BitLocker is enabled.
- question: |
Can BitLocker support smart cards for pre-boot authentication?
answer: |
BitLocker doesn't support smart cards for pre-boot authentication. There's no single industry standard for smart card support in the firmware, and most computers either don't implement firmware support for smart cards, or only support specific smart cards and readers. This lack of standardization makes supporting them difficult.
- question: |
Can I use a non-Microsoft TPM driver?
answer: |
Microsoft doesn't support non-Microsoft TPM drivers and strongly recommends against using them with BitLocker. Attempting to use a non-Microsoft TPM driver with BitLocker may cause BitLocker to report that a TPM isn't present on the computer and not allow the TPM to be used with BitLocker.
- question: |
Can other tools that manage or modify the master boot record work with BitLocker?
answer: |
We don't recommend modifying the master boot record on computers whose operating system drives are BitLocker-protected for several security, reliability, and product support reasons. Changes to the master boot record (MBR) could change the security environment and prevent the computer from starting normally and complicate any efforts to recover from a corrupted MBR. Changes made to the MBR by anything other than Windows might force the computer into recovery mode or prevent it from booting entirely.
- question: |
Why is the system check failing when I'm encrypting my operating system drive?
answer: |
The system check is designed to ensure the computer's BIOS or UEFI firmware is compatible with BitLocker and that the TPM is working correctly. The system check can fail for several reasons:
- The computer's BIOS or UEFI firmware can't read USB flash drives.
- The computer's BIOS, uEFI firmware, or boot menu doesn't have reading USB flash drives enabled.
- There are multiple USB flash drives inserted into the computer.
- The PIN wasn't entered correctly.
- The computer's BIOS or UEFI firmware only supports using the function keys (F1-F10) to enter numerals in the pre-boot environment.
- The startup key was removed before the computer finished rebooting.
- The TPM has malfunctioned and fails to unseal the keys.
- question: |
What can I do if the recovery key on my USB flash drive can't be read?
answer: |
Some computers can't read USB flash drives in the pre-boot environment. First, check the BIOS or UEFI firmware and boot settings to ensure that the use of USB drives is enabled. If it isn't enabled, enable the use of USB drives in the BIOS or UEFI firmware and boot settings, and then try to read the recovery key from the USB flash drive again. If the USB flash drive still can't be read, the hard drive will need to be mounted as a data drive on another computer so that there's an operating system to attempt to read the recovery key from the USB flash drive. If the USB flash drive has been corrupted or damaged, a recovery password may need to be supplied or use the recovery information that was backed up to AD DS. Also, if the recovery key is being used in the pre-boot environment, ensure that the drive is formatted by using the NTFS, FAT16, or FAT32 file system.
- question: |
Why am I unable to save my recovery key to my USB flash drive?
answer: |
The **Save to USB** option isn't shown by default for removable drives. If the option is unavailable, it means that a system administrator has disallowed the use of recovery keys.
- question: |
Why am I unable to automatically unlock my drive?
answer: |
Automatic unlocking for fixed data drives requires the operating system drive to also be protected by BitLocker. If a computer is being used that doesn't have a BitLocker-protected operating system drive, then the fixed drive can't be automatically unlocked. For removable data drives, automatic unlocking can be added by right-clicking the drive in Windows Explorer and selecting **Manage BitLocker**. Password or smart card credentials that were supplied when BitLocker was turned on can still be used to unlock the removable drive on other computers.
- question: |
Can I use BitLocker in Safe Mode?
answer: |
Limited BitLocker functionality is available in Safe Mode. BitLocker-protected drives can be unlocked and decrypted by using the **BitLocker Drive Encryption** Control Panel item. Right-clicking to access BitLocker options from Windows Explorer isn't available in Safe Mode.
- question: |
How do I "lock" a data drive?
answer: |
Both fixed and removable data drives can be locked by using the Manage-bde command-line tool and the -lock command.
> [!NOTE]
> Ensure all data is saved to the drive before locking it. Once locked, the drive will become inaccessible.
The syntax of this command is:
```cmd
manage-bde.exe <driveletter> -lock
````
Outside of using this command, data drives will be locked on shutdown and restart of the operating system. A removable data drive will also be locked automatically when the drive is removed from the computer.
- question: |
Can I use BitLocker with the Volume Shadow Copy Service?
answer: |
Yes. However, shadow copies made prior to enabling BitLocker will be automatically deleted when BitLocker is enabled on software-encrypted drives. If a hardware encrypted drive is being used, the shadow copies are retained.
- question: |
Does BitLocker support virtual hard disks (VHDs)?
answer: |
BitLocker should work like any specific physical machine within its hardware limitations as long as the environment (physical or virtual) meets Windows Operating System requirements to run.
- With TPM: Yes, it's supported.
- Without TPM: Yes, it's supported (with password protector).
BitLocker is also supported on data volume VHDs, such as those used by clusters, if running Windows 10, Windows 8.1, Windows 8, Windows Server 2016, Windows Server 2012 R2, or Windows Server 2012.
- question: |
Can I use BitLocker with virtual machines (VMs)?
answer: |
Yes. Password protectors and virtual TPMs can be used with BitLocker to protect virtual machines. VMs can be domain joined, Azure AD-joined, or workplace-joined (via **Settings** > **Accounts** > **Access work or school** > **Connect**) to receive policy. Encryption can be enabled either while creating the VM or by using other existing management tools such as the BitLocker CSP, or even by using a startup script or sign-in script delivered by Group Policy. Windows Server 2016 also supports [Shielded VMs and guarded fabric](/windows-server/virtualization/guarded-fabric-shielded-vm/guarded-fabric-and-shielded-vms-top-node) to protect VMs from malicious administrators.

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---
title: Prepare the organization for BitLocker Planning and policies
description: This article for the IT professional explains how can to plan for a BitLocker deployment.
ms.topic: conceptual
ms.date: 11/08/2022
---
# Prepare an organization for BitLocker: Planning and policies
This article for the IT professional explains how to plan BitLocker deployment.
When BitLocker deployment strategy is defined, define the appropriate policies and configuration requirements based on the business requirements of the organization. The following sections will help with collecting information. Use this information to help with the decision-making process about deploying and managing BitLocker systems.
## Audit the environment
To plan a BitLocker deployment, understand the current environment. Perform an informal audit to define the current policies, procedures, and hardware environment. Review the existing disk encryption software corporate security policies. If the organization isn't using disk encryption software, then none of these policies will exist. If disk encryption software is being used, then the organization's policies might need to be changed to use the BitLocker features.
To help document the organization's current disk encryption security policies, answer the following questions:
1. Are there policies to determine which computers will use BitLocker and which computers won't use BitLocker?
2. What policies exist to control recovery password and recovery key storage?
3. What are the policies for validating the identity of users who need to perform BitLocker recovery?
4. What policies exist to control who in the organization has access to recovery data?
5. What policies exist to control computer decommissioning or retirement?
## Encryption keys and authentication
BitLocker helps prevent unauthorized access to data on lost or stolen computers by:
- Encrypting the entire Windows operating system volume on the hard disk.
- Verifying the boot process integrity.
The trusted platform module (TPM) is a hardware component installed in many newer computers by the computer manufacturers. It works with BitLocker to help protect user data. And, help make sure a computer hasn't been tampered with while the system was offline.
Also, BitLocker can lock the normal startup process until the user supplies a personal identification number (PIN) or inserts a removable USB device that contains a startup key. These extra security measures provide multifactor authentication. They also make sure that the computer won't start or resume from hibernation until the correct PIN or startup key is presented.
On computers that don't have a TPM version 1.2 or higher, BitLocker can still be used to encrypt the Windows operating system volume. However, this implementation requires the user to insert a USB startup key to start the computer or resume from hibernation. It doesn't provide the pre-startup system integrity verification offered by BitLocker working with a TPM.
### BitLocker key protectors
| Key protector | Description |
| - | - |
| *TPM* | A hardware device used to help establish a secure root-of-trust. BitLocker only supports TPM 1.2 or higher versions.|
| *PIN* | A user-entered numeric key protector that can only be used in addition to the TPM.|
| *Enhanced PIN* | A user-entered alphanumeric key protector that can only be used in addition to the TPM.|
| *Startup key* | An encryption key that can be stored on most removable media. This key protector can be used alone on non-TPM computers, or with a TPM for added security.|
| *Recovery password* | A 48-digit number used to unlock a volume when it is in recovery mode. Numbers can often be typed on a regular keyboard. If the numbers on the normal keyboard aren't responding, the function keys (F1-F10) can be used to input the numbers.|
| *Recovery key*| An encryption key stored on removable media that can be used for recovering data encrypted on a BitLocker volume.|
### BitLocker authentication methods
| Authentication method | Requires user interaction | Description |
| - | - | - |
| *TPM only*| No| TPM validates early boot components.|
| *TPM + PIN* | Yes| TPM validates early boot components. The user must enter the correct PIN before the start-up process can continue, and before the drive can be unlocked. The TPM enters lockout if the incorrect PIN is entered repeatedly, to protect the PIN from brute force attacks. The number of repeated attempts that will trigger a lockout is variable.|
| *TPM + Network key* | No | The TPM successfully validates early boot components, and a valid encrypted network key has been provided from the WDS server. This authentication method provides automatic unlock of operating system volumes at system reboot while still maintaining multifactor authentication. |
| *TPM + startup key* | Yes| The TPM successfully validates early boot components, and a USB flash drive containing the startup key has been inserted.|
| *Startup key only* | Yes| The user is prompted for the USB flash drive that has the recovery key and/or startup key, and then reboot the computer.|
#### Will computers without TPM 1.2 or higher versions be supported?
Determine whether computers that don't have a TPM 1.2 or higher versions in the environment will be supported. If it's decided to support computers with TPM 1.2 or higher versions, a user must use a USB startup key to boot the system. This startup key requires extra support processes similar to multifactor authentication.
#### What areas of the organization need a baseline level of data protection?
The TPM-only authentication method provides the most transparent user experience for organizations that need a baseline level of data protection to meet security policies. It has the lowest total cost of ownership. TPM-only might also be more appropriate for computers that are unattended or that must reboot unattended.
However, TPM-only authentication method offers the lowest level of data protection. This authentication method protects against attacks that modify early boot components. But, the level of protection can be affected by potential weaknesses in hardware or in the early boot components. BitLocker's multifactor authentication methods significantly increase the overall level of data protection.
#### What areas of the organization need a more secure level of data protection?
If there are user computers with highly sensitive data, then deploy BitLocker with multifactor authentication on those systems. Requiring the user to input a PIN significantly increases the level of protection for the system. BitLocker Network Unlock can also be used to allow these computers to automatically unlock when connected to a trusted wired network that can provide the Network Unlock key.
#### What multifactor authentication method does the organization prefer?
The protection differences provided by multifactor authentication methods can't be easily quantified. Consider each authentication method's impact on Helpdesk support, user education, user productivity, and any automated systems management processes.
## TPM hardware configurations
In the deployment plan, identify what TPM-based hardware platforms will be supported. Document the hardware models from an OEM(s) being used by the organization so that their configurations can be tested and supported. TPM hardware requires special consideration during all aspects of planning and deployment.
### TPM 1.2 states and initialization
For TPM 1.2, there are multiple possible states. Windows automatically initializes the TPM, which brings it to an enabled, activated, and owned state. This state is the state that BitLocker requires before it can use the TPM.
### Endorsement keys
For a TPM to be usable by BitLocker, it must contain an endorsement key, which is an RSA key pair. The private half of the key pair is held inside the TPM and is never revealed or accessible outside the TPM. If the TPM doesn't have an endorsement key, BitLocker will force the TPM to generate one automatically as part of BitLocker setup.
An endorsement key can be created at various points in the TPM's lifecycle, but needs to be created only once for the lifetime of the TPM. If an endorsement key doesn't exist for the TPM, it must be created before TPM ownership can be taken.
For more information about the TPM and the TCG, see the Trusted Computing Group: Trusted Platform Module (TPM) Specifications (<https://go.microsoft.com/fwlink/p/?linkid=69584>).
## Non-TPM hardware configurations
Devices that don't include a TPM can still be protected by drive encryption. Windows To Go workspaces can be BitLocker protected using a startup password and PCs without a TPM can use a startup key.
Use the following questions to identify issues that might affect the deployment in a non-TPM configuration:
- Are password complexity rules in place?
- Is there a budget for USB flash drives for each of these computers?
- Do existing non-TPM devices support USB devices at boot time?
Test the individual hardware platforms with the BitLocker system check option while enabling BitLocker. The system check makes sure that BitLocker can read the recovery information from a USB device and encryption keys correctly before it encrypts the volume. CD and DVD drives can't act as a block storage device and can't be used to store the BitLocker recovery material.
## Disk configuration considerations
To function correctly, BitLocker requires a specific disk configuration. BitLocker requires two partitions that meet the following requirements:
- The operating system partition contains the operating system and its support files; it must be formatted with the NTFS file system
- The system partition (or boot partition) includes the files needed to load Windows after the BIOS or UEFI firmware has prepared the system hardware. BitLocker isn't enabled on this partition. For BitLocker to work, the system partition must not be encrypted, and must be on a different partition than the operating system. On UEFI platforms, the system partition must be formatted with the FAT 32-file system. On BIOS platforms, the system partition must be formatted with the NTFS file system. It should be at least 350 MB in size.
Windows setup automatically configures the disk drives of computers to support BitLocker encryption.
Windows Recovery Environment (Windows RE) is an extensible recovery platform that is based on Windows Pre-installation Environment (Windows PE). When the computer fails to start, Windows automatically transitions into this environment, and the Startup Repair tool in Windows RE automates the diagnosis and repair of an unbootable Windows installation. Windows RE also contains the drivers and tools that are needed to unlock a volume protected by BitLocker by providing a recovery key or recovery password. To use Windows RE with BitLocker, the Windows RE boot image must be on a volume that isn't protected by BitLocker.
Windows RE can also be used from boot media other than the local hard disk. If Windows RE isn't installed on the local hard disk of BitLocker-enabled computers, then different methods can be used to boot Windows RE. For example, Windows Deployment Services (WDS), CD-ROM, or USB flash drive can be used for recovery.
## BitLocker provisioning
In Windows Vista and Windows 7, BitLocker was provisioned after the installation for system and data volumes. It used the `manage-bde` command line interface or the Control Panel user interface. With newer operating systems, BitLocker can be provisioned before the operating system is installed. Preprovisioning requires the computer have a TPM.
To check the BitLocker status of a particular volume, administrators can look at the drive status in the BitLocker control panel applet or Windows Explorer. The "Waiting For Activation" status with a yellow exclamation icon means that the drive was preprovisioned for BitLocker. This status means that there was only a clear protector used when encrypting the volume. In this case, the volume isn't protected, and needs to have a secure key added to the volume before the drive is considered fully protected. Administrators can use the control panel options, the **manage-bde** tool, or WMI APIs to add an appropriate key protector. The volume status will be updated.
When using the control panel options, administrators can choose to **Turn on BitLocker** and follow the steps in the wizard to add a protector, such as a PIN for an operating system volume (or a password if no TPM exists), or a password or smart card protector to a data volume. Then the drive security window is presented before changing the volume status.
Administrators can enable BitLocker before to operating system deployment from the Windows Pre-installation Environment (WinPE). This step is done with a randomly generated clear key protector applied to the formatted volume. It encrypts the volume before running the Windows setup process. If the encryption uses the Used Disk Space Only option, then this step takes only a few seconds. And, it incorporates into the regular deployment processes.
## Used Disk Space Only encryption
The BitLocker Setup wizard provides administrators the ability to choose the Used Disk Space Only or Full encryption method when enabling BitLocker for a volume. Administrators can use the new BitLocker group policy setting to enforce either Used Disk Space Only or Full disk encryption.
Launching the BitLocker Setup wizard prompts for the authentication method to be used (password and smart card are available for data volumes). Once the method is chosen and the recovery key is saved, the wizard asks to choose the drive encryption type. Select Used Disk Space Only or Full drive encryption.
With Used Disk Space Only, just the portion of the drive that contains data will be encrypted. Unused space will remain unencrypted. This behavior causes the encryption process to be much faster, especially for new PCs and data drives. When BitLocker is enabled with this method, as data is added to the drive, the portion of the drive used is encrypted. So, there's never unencrypted data stored on the drive.
With Full drive encryption, the entire drive is encrypted, whether data is stored on it or not. This option is useful for drives that have been repurposed, and may contain data remnants from their previous use.
## Active Directory Domain Services considerations
BitLocker integrates with Active Directory Domain Services (AD DS) to provide centralized key management. By default, no recovery information is backed up to Active Directory. Administrators can configure the following group policy setting for each drive type to enable backup of BitLocker recovery information:
**Computer Configuration** > **Administrative Templates** > **Windows Components** > **BitLocker Drive Encryption** > ***drive type*** > **Choose how BitLocker-protected drives can be recovered**.
By default, only Domain Admins have access to BitLocker recovery information, but [access can be delegated to others](/archive/blogs/craigf/delegating-access-in-ad-to-bitlocker-recovery-information).
The following recovery data is saved for each computer object:
- **Recovery password**
A 48-digit recovery password used to recover a BitLocker-protected volume. Users enter this password to unlock a volume when BitLocker enters recovery mode.
- **Key package data**
With this key package and the recovery password, portions of a BitLocker-protected volume can be decrypted if the disk is severely damaged. Each key package works only with the volume it was created on, which is identified by the corresponding volume ID.
## FIPS support for recovery password protector
Functionality introduced in Windows Server 2012 R2 and Windows 8.1 allows BitLocker to be fully functional in FIPS mode.
> [!NOTE]
> The United States Federal Information Processing Standard (FIPS) defines security and interoperability requirements for computer systems that are used by the U.S. Federal Government. The FIPS-140 standard defines approved cryptographic algorithms. The FIPS-140 standard also sets forth requirements for key generation and for key management. The National Institute of Standards and Technology (NIST) uses the Cryptographic Module Validation Program (CMVP) to determine whether a particular implementation of a cryptographic algorithm is compliant with the FIPS-140 standard. An implementation of a cryptographic algorithm is considered FIPS-140-compliant only if it has been submitted for and has passed NIST validation. An algorithm that has not been submitted cannot be considered FIPS-compliant even if the implementation produces identical data as a validated implementation of the same algorithm.
Before these supported versions of Windows, when Windows was in FIPS mode, BitLocker prevented the creation or use of recovery passwords and instead forced the user to use recovery keys. For more information about these issues, see the support article [The recovery password for Windows BitLocker isn't available when FIPS compliant policy is set in Windows](/troubleshoot/windows-client/windows-security/bitlocker-recovery-password-not-fips-compliant).
However, on computers running these supported systems with BitLocker enabled:
- FIPS-compliant recovery password protectors can be created when Windows is in FIPS mode. These protectors use the FIPS-140 NIST SP800-132 algorithm.
- Recovery passwords created in FIPS mode on Windows 8.1 can be distinguished from recovery passwords created on other systems.
- Recovery unlock using the FIPS-compliant, algorithm-based recovery password protector works in all cases that currently work for recovery passwords.
- When FIPS-compliant recovery passwords unlock volumes, the volume is unlocked to allow read/write access even while in FIPS mode.
- FIPS-compliant recovery password protectors can be exported and stored in AD a while in FIPS mode.
The BitLocker Group Policy settings for recovery passwords work the same for all Windows versions that support BitLocker, whether in FIPS mode or not.
On Windows Server 2012 R2 and Windows 8.1 and older, recovery passwords generated on a system in FIPS mode can't be used. Recovery passwords created on Windows Server 2012 R2 and Windows 8.1 are incompatible with BitLocker on operating systems older than Windows Server 2012 R2 and Windows 8.1. So, recovery keys should be used instead.
## Related articles
- [Trusted Platform Module](../tpm/trusted-platform-module-top-node.md)
- [TPM Group Policy settings](../tpm/trusted-platform-module-services-group-policy-settings.md)
- [BitLocker frequently asked questions (FAQ)](bitlocker-frequently-asked-questions.yml)
- [BitLocker](bitlocker-overview.md)
- [BitLocker Group Policy settings](bitlocker-group-policy-settings.md)
- [BitLocker basic deployment](bitlocker-basic-deployment.md)

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---
title: Protecting cluster shared volumes and storage area networks with BitLocker
description: This article for IT pros describes how to protect CSVs and SANs with BitLocker.
ms.reviewer:
ms.prod: windows-client
ms.localizationpriority: medium
author: frankroj
ms.author: frankroj
manager: aaroncz
ms.topic: conceptual
ms.date: 11/08/2022
ms.custom: bitlocker
ms.technology: itpro-security
---
# Protecting cluster shared volumes and storage area networks with BitLocker
**Applies to:**
- Windows Server 2016 and above
This article describes the procedure to protect cluster shared volumes (CSVs) and storage area networks (SANs) by using BitLocker.
BitLocker protects both physical disk resources and cluster shared volumes version 2.0 (CSV2.0). BitLocker on clustered volumes provides an extra layer of protection that can be used by administrators wishing to protect sensitive, highly available data. The administrators use this extra layer of protection to increase the security to resources. Only certain user accounts provided access to unlock the BitLocker volume.
## Configuring BitLocker on Cluster Shared Volumes
### Using BitLocker with clustered volumes
Volumes within a cluster are managed with the help of BitLocker based on how the cluster service "views" the volume to be protected. The volume can be a physical disk resource such as a logical unit number (LUN) on a SAN or network attached storage (NAS).
> [!IMPORTANT]
> SANs used with BitLocker must have obtained Windows Hardware Certification. For more info, see [Windows Hardware Lab Kit](/windows-hardware/drivers/).
Instead, the volume can be a cluster-shared volume. Windows Server 2012 expanded the CSV architecture, now known as CSV2.0, to enable support for BitLocker. The volumes that are designated for a cluster must do the following tasks:
- It must turn on BitLocker—only after this task is done, can the volumes be added to the storage pool.
- It must put the resource into maintenance mode before BitLocker operations are completed.
Windows PowerShell or the `manage-bde.exe` command-line tool is the preferred method to manage BitLocker on CSV2.0 volumes. This method is recommended over the BitLocker Control Panel item because CSV2.0 volumes are mount points. Mount points are an NTFS object that is used to provide an entry point to other volumes. Mount points don't require the use of a drive letter. Volumes that lack drive letters don't appear in the BitLocker Control Panel item. Additionally, the new Active Directory-based protector option required for cluster disk resource or CSV2.0 resources isn't available in the Control Panel item.
> [!NOTE]
> Mount points can be used to support remote mount points on SMB-based network shares. This type of share is not supported for BitLocker encryption.
If there's a thinly provisioned storage, such as a dynamic virtual hard disk (VHD), BitLocker runs in **Used Disk Space Only** encryption mode. The **`manage-bde.exe -WipeFreeSpace`** command can't be used to transition the volume to full-volume encryption on thinly provisioned storage volumes. The usage of **`manage-bde.exe -WipeFreeSpace`** command is blocked to avoid expanding thinly provisioned volumes to occupy the entire backing store while wiping the unoccupied (free) space.
### Active Directory-based protector
An Active Directory Domain Services (AD DS) protector can also be used for protecting clustered volumes held within the AD DS infrastructure. The **ADAccountOrGroup** protector is a domain security identifier (SID)-based protector that can be bound to a user account, machine account, or group. When an unlock request is made for a protected volume, the following events take place:
- BitLocker service interrupts the request and uses the BitLocker protect/unprotect APIs to unlock or deny the request.
- BitLocker will unlock protected volumes without user intervention by attempting protectors in the following order:
1. Clear key
2. Driver-based auto-unlock key
3. **ADAccountOrGroup** protector
a. Service context protector
b. User protector
4. Registry-based auto-unlock key
> [!NOTE]
> A Windows Server 2012 or later domain controller is required for this feature to work properly.
### Turning on BitLocker before adding disks to a cluster using Windows PowerShell
BitLocker encryption is available for disks before these disks are added to a cluster storage pool.
> [!NOTE]
> The advantage of The Bitlocker encryption can even be made available for disks after they are added to a cluster storage pool.
The advantage of encrypting volumes prior to adding them to a cluster is that the disk resource need not be suspended to complete the operation.
To turn on BitLocker for a disk before adding it to a cluster:
1. Install the BitLocker Drive Encryption feature if it isn't already installed.
2. Ensure the disk is an NTFS-formatted one and has a drive letter assigned to it.
3. Identify the name of the cluster with Windows PowerShell.
```powershell
Get-Cluster
```
4. Enable BitLocker on a volume with an **ADAccountOrGroup** protector, using the cluster name. For example, use a command such as:
```powershell
Enable-BitLocker E: -ADAccountOrGroupProtector -ADAccountOrGroup CLUSTER$
```
> [!WARNING]
> An **ADAccountOrGroup** protector must be configured using the cluster CNO for a BitLocker enabled volume to either be shared in a Cluster Shared Volume or to fail over properly in a traditional failover cluster.
5. Repeat the preceding steps for each disk in the cluster.
6. Add the volume(s) to the cluster.
### Turning on BitLocker for a clustered disk using Windows PowerShell
When the cluster service owns a disk resource already, the disk resource needs to be set into maintenance mode before BitLocker can be enabled. To turn on the BitLocker for a clustered disk using Windows PowerShell, perform the following steps:
1. Install the BitLocker drive encryption feature if it isn't already installed.
2. Check the status of the cluster disk using Windows PowerShell.
```powershell
Get-ClusterResource "Cluster Disk 1"
```
3. Put the physical disk resource into maintenance mode using Windows PowerShell.
```powershell
Get-ClusterResource "Cluster Disk 1" | Suspend-ClusterResource
```
4. Identify the name of the cluster with Windows PowerShell.
```powershell
Get-Cluster
```
5. Enable BitLocker a volume with an **ADAccountOrGroup** protector, using the cluster name. For example, use a command such as:
```powershell
Enable-BitLocker E: -ADAccountOrGroupProtector -ADAccountOrGroup CLUSTER$
```
> [!WARNING]
> An **ADAccountOrGroup** protector must be configured using the cluster CNO for a BitLocker-enabled volume to either be shared in a cluster-shared Volume or to fail over properly in a traditional failover cluster.
6. Use **Resume-ClusterResource** to take back the physical disk resource out of maintenance mode:
```powershell
Get-ClusterResource "Cluster Disk 1" | Resume-ClusterResource
```
7. Repeat the preceding steps for each disk in the cluster.
### Adding BitLocker-encrypted volumes to a cluster using `manage-bde.exe`
**`Manage-bde.exe`** can also be used to enable BitLocker on clustered volumes. The steps needed to add a physical disk resource or CSV2.0 volume to an existing cluster are:
1. Verify that the BitLocker drive encryption feature is installed on the computer.
2. Ensure new storage is formatted as NTFS.
3. Encrypt the volume, add a recovery key and add the cluster administrator as a protector key using **`manage-bde.exe`** in a command prompt window. For example:
```cmd
manage-bde.exe -on -used <drive letter> -RP -sid domain\CNO$ -sync
```
1. BitLocker will check to see if the disk is already part of a cluster. If it is, administrators will encounter a hard block. Otherwise, the encryption continues.
2. Using the -sync parameter is optional. However, using the -sync parameter has the advantage of ensuring the command waits until the encryption for the volume is completed. The volume is then released for use in the cluster storage pool.
4. Open the Failover Cluster Manager snap-in or cluster PowerShell cmdlets to enable the disk to be clustered.
- Once the disk is clustered, it's enabled for CSV.
5. During the resource online operation, cluster checks whether the disk is BitLocker encrypted.
1. If the volume isn't BitLocker enabled, traditional cluster online operations occur.
2. If the volume is BitLocker enabled, BitLocker checks if the volume is **locked**. If the volume is **locked**, BitLocker impersonates the CNO and unlocks the volume using the CNO protector. If these actions by BitLocker fail, an event is logged. The logged event will state that the volume couldn't be unlocked and the online operation has failed.
6. Once the disk is online in the storage pool, it can be added to a CSV by right-clicking the disk resource, and choosing "**Add to cluster shared volumes**".
CSVs include both encrypted and unencrypted volumes. To check the status of a particular volume for BitLocker encryption run the `manage-bde.exe -status` command as an administrator with a path to the volume. The path must be one that is inside the CSV namespace. For example:
```cmd
manage-bde.exe -status "C:\ClusterStorage\volume1"
```
### Physical disk resources
Unlike CSV2.0 volumes, physical disk resources can only be accessed by one cluster node at a time. This condition means that operations such as encrypting, decrypting, locking, or unlocking volumes require a context to perform. For example, a physical disk resource can't unlock or decrypt if it isn't administering the cluster node that owns the disk resource because the disk resource isn't available.
### Restrictions on BitLocker actions with cluster volumes
The following table contains information about both physical disk resources (that is, traditional failover cluster volumes) and cluster shared volumes (CSV) and the actions that are allowed by BitLocker in each situation.
| Action | On owner node of failover volume | On Metadata Server (MDS) of CSV | On (Data Server) DS of CSV | Maintenance Mode |
|--- |--- |--- |--- |--- |
|**`Manage-bde.exe -on`**|Blocked|Blocked|Blocked|Allowed|
|**`Manage-bde.exe -off`**|Blocked|Blocked|Blocked|Allowed|
|**`Manage-bde.exe Pause/Resume`**|Blocked|Blocked**|Blocked|Allowed|
|**`Manage-bde.exe -lock`**|Blocked|Blocked|Blocked|Allowed|
|**`Manage-bde.exe -wipe`**|Blocked|Blocked|Blocked|Allowed|
|**Unlock**|Automatic via cluster service|Automatic via cluster service|Automatic via cluster service|Allowed|
|**`Manage-bde.exe -protector -add`**|Allowed|Allowed|Blocked|Allowed|
|**`Manage-bde.exe -protector -delete`**|Allowed|Allowed|Blocked|Allowed|
|**`Manage-bde.exe -autounlock`**|Allowed (not recommended)|Allowed (not recommended)|Blocked|Allowed (not recommended)|
|**`Manage-bde.exe -upgrade`**|Allowed|Allowed|Blocked|Allowed|
|**Shrink**|Allowed|Allowed|Blocked|Allowed|
|**Extend**|Allowed|Allowed|Blocked|Allowed|
> [!NOTE]
> Although the **`manage-bde.exe -pause`** command is blocked in clusters, the cluster service automatically resumes a paused encryption or decryption from the MDS node.
In the case where a physical disk resource experiences a failover event during conversion, the new owning node detects that the conversion isn't complete and completes the conversion process.
### Other considerations when using BitLocker on CSV2.0
Some other considerations to take into account for BitLocker on clustered storage include:
- BitLocker volumes have to be initialized and begin encryption before they're available to add to a CSV2.0 volume.
- If an administrator needs to decrypt a CSV volume, remove the volume from the cluster or put it into disk maintenance mode. The CSV can be added back to the cluster while waiting for decryption to complete.
- If an administrator needs to start encrypting a CSV volume, remove the volume from the cluster or put it into maintenance mode.
- If conversion is paused with encryption in progress and the CSV volume is offline from the cluster, the cluster thread (health check) automatically resumes conversion when the volume is online to the cluster.
- If conversion is paused with encryption in progress and a physical disk resource volume is offline from the cluster, the BitLocker driver automatically resumes conversion when the volume is online to the cluster.
- If conversion is paused with encryption in progress, while the CSV volume is in maintenance mode, the cluster thread (health check) automatically resumes conversion when moving the volume back from maintenance.
- If conversion is paused with encryption in progress, while the disk resource volume is in maintenance mode, the BitLocker driver automatically resumes conversion when the volume is moved back from maintenance mode.

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items:
- name: Overview
href: bitlocker-overview.md
- name: BitLocker device encryption
href: bitlocker-device-encryption-overview-windows-10.md
- name: BitLocker frequently asked questions (FAQ)
href: bitlocker-frequently-asked-questions.yml
items:
- name: Overview and requirements
href: bitlocker-overview-and-requirements-faq.yml
- name: Upgrading
href: bitlocker-upgrading-faq.yml
- name: Deployment and administration
href: bitlocker-deployment-and-administration-faq.yml
- name: Key management
href: bitlocker-key-management-faq.yml
- name: BitLocker To Go
href: bitlocker-to-go-faq.yml
- name: Active Directory Domain Services
href: bitlocker-and-adds-faq.yml
- name: Security
href: bitlocker-security-faq.yml
- name: BitLocker Network Unlock
href: bitlocker-network-unlock-faq.yml
- name: General
href: bitlocker-using-with-other-programs-faq.yml
- name: "Prepare your organization for BitLocker: Planning and policies"
href: prepare-your-organization-for-bitlocker-planning-and-policies.md
- name: BitLocker deployment comparison
href: bitlocker-deployment-comparison.md
- name: BitLocker basic deployment
href: bitlocker-basic-deployment.md
- name: Deploy BitLocker on Windows Server 2012 and later
href: bitlocker-how-to-deploy-on-windows-server.md
- name: BitLocker management
href: bitlocker-management-for-enterprises.md
- name: Enable Network Unlock with BitLocker
href: bitlocker-how-to-enable-network-unlock.md
- name: Use BitLocker Drive Encryption Tools to manage BitLocker
href: bitlocker-use-bitlocker-drive-encryption-tools-to-manage-bitlocker.md
- name: Use BitLocker Recovery Password Viewer
href: bitlocker-use-bitlocker-recovery-password-viewer.md
- name: BitLocker Group Policy settings
href: bitlocker-group-policy-settings.md
- name: BCD settings and BitLocker
href: bcd-settings-and-bitlocker.md
- name: BitLocker Recovery Guide
href: bitlocker-recovery-guide-plan.md
- name: BitLocker Countermeasures
href: bitlocker-countermeasures.md
- name: Protecting cluster shared volumes and storage area networks with BitLocker
href: protecting-cluster-shared-volumes-and-storage-area-networks-with-bitlocker.md
- name: Troubleshoot BitLocker
items:
- name: Troubleshoot BitLocker
href: /troubleshoot/windows-client/windows-security/bitlocker-issues-troubleshooting
- name: "BitLocker cannot encrypt a drive: known issues"
href: /troubleshoot/windows-client/windows-security/bitlocker-cannot-encrypt-a-drive-known-issues
- name: "Enforcing BitLocker policies by using Intune: known issues"
href: /troubleshoot/windows-client/windows-security/enforcing-bitlocker-policies-by-using-intune-known-issues
- name: "BitLocker Network Unlock: known issues"
href: /troubleshoot/windows-client/windows-security/bitlocker-network-unlock-known-issues
- name: "BitLocker recovery: known issues"
href: /troubleshoot/windows-client/windows-security/bitlocker-recovery-known-issues
- name: "BitLocker configuration: known issues"
href: /troubleshoot/windows-client/windows-security/bitlocker-configuration-known-issues
- name: Troubleshoot BitLocker and TPM issues
items:
- name: "BitLocker cannot encrypt a drive: known TPM issues"
href: /troubleshoot/windows-client/windows-security/bitlocker-cannot-encrypt-a-drive-known-tpm-issues
- name: "BitLocker and TPM: other known issues"
href: /troubleshoot/windows-client/windows-security/bitlocker-and-tpm-other-known-issues
- name: Decode Measured Boot logs to track PCR changes
href: /troubleshoot/windows-client/windows-security/decode-measured-boot-logs-to-track-pcr-changes

74
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@ -2,79 +2,7 @@ items:
- name: Overview
href: index.md
- name: BitLocker
href: ../../information-protection/bitlocker/bitlocker-overview.md
items:
- name: Overview of BitLocker Device Encryption in Windows
href: ../../information-protection/bitlocker/bitlocker-device-encryption-overview-windows-10.md
- name: BitLocker frequently asked questions (FAQ)
href: ../../information-protection/bitlocker/bitlocker-frequently-asked-questions.yml
items:
- name: Overview and requirements
href: ../../information-protection/bitlocker/bitlocker-overview-and-requirements-faq.yml
- name: Upgrading
href: ../../information-protection/bitlocker/bitlocker-upgrading-faq.yml
- name: Deployment and administration
href: ../../information-protection/bitlocker/bitlocker-deployment-and-administration-faq.yml
- name: Key management
href: ../../information-protection/bitlocker/bitlocker-key-management-faq.yml
- name: BitLocker To Go
href: ../../information-protection/bitlocker/bitlocker-to-go-faq.yml
- name: Active Directory Domain Services
href: ../../information-protection/bitlocker/bitlocker-and-adds-faq.yml
- name: Security
href: ../../information-protection/bitlocker/bitlocker-security-faq.yml
- name: BitLocker Network Unlock
href: ../../information-protection/bitlocker/bitlocker-network-unlock-faq.yml
- name: General
href: ../../information-protection/bitlocker/bitlocker-using-with-other-programs-faq.yml
- name: "Prepare your organization for BitLocker: Planning and policies"
href: ../../information-protection/bitlocker/prepare-your-organization-for-bitlocker-planning-and-policies.md
- name: BitLocker deployment comparison
href: ../../information-protection/bitlocker/bitlocker-deployment-comparison.md
- name: BitLocker basic deployment
href: ../../information-protection/bitlocker/bitlocker-basic-deployment.md
- name: Deploy BitLocker on Windows Server 2012 and later
href: ../../information-protection/bitlocker/bitlocker-how-to-deploy-on-windows-server.md
- name: BitLocker management
href: ../../information-protection/bitlocker/bitlocker-management-for-enterprises.md
- name: Enable Network Unlock with BitLocker
href: ../../information-protection/bitlocker/bitlocker-how-to-enable-network-unlock.md
- name: Use BitLocker Drive Encryption Tools to manage BitLocker
href: ../../information-protection/bitlocker/bitlocker-use-bitlocker-drive-encryption-tools-to-manage-bitlocker.md
- name: Use BitLocker Recovery Password Viewer
href: ../../information-protection/bitlocker/bitlocker-use-bitlocker-recovery-password-viewer.md
- name: BitLocker Group Policy settings
href: ../../information-protection/bitlocker/bitlocker-group-policy-settings.md
- name: BCD settings and BitLocker
href: ../../information-protection/bitlocker/bcd-settings-and-bitlocker.md
- name: BitLocker Recovery Guide
href: ../../information-protection/bitlocker/bitlocker-recovery-guide-plan.md
- name: BitLocker Countermeasures
href: ../../information-protection/bitlocker/bitlocker-countermeasures.md
- name: Protecting cluster shared volumes and storage area networks with BitLocker
href: ../../information-protection/bitlocker/protecting-cluster-shared-volumes-and-storage-area-networks-with-bitlocker.md
- name: Troubleshoot BitLocker
items:
- name: Troubleshoot BitLocker
href: /troubleshoot/windows-client/windows-security/bitlocker-issues-troubleshooting
- name: "BitLocker cannot encrypt a drive: known issues"
href: /troubleshoot/windows-client/windows-security/bitlocker-cannot-encrypt-a-drive-known-issues
- name: "Enforcing BitLocker policies by using Intune: known issues"
href: /troubleshoot/windows-client/windows-security/enforcing-bitlocker-policies-by-using-intune-known-issues
- name: "BitLocker Network Unlock: known issues"
href: /troubleshoot/windows-client/windows-security/bitlocker-network-unlock-known-issues
- name: "BitLocker recovery: known issues"
href: /troubleshoot/windows-client/windows-security/bitlocker-recovery-known-issues
- name: "BitLocker configuration: known issues"
href: /troubleshoot/windows-client/windows-security/bitlocker-configuration-known-issues
- name: Troubleshoot BitLocker and TPM issues
items:
- name: "BitLocker cannot encrypt a drive: known TPM issues"
href: /troubleshoot/windows-client/windows-security/bitlocker-cannot-encrypt-a-drive-known-tpm-issues
- name: "BitLocker and TPM: other known issues"
href: /troubleshoot/windows-client/windows-security/bitlocker-and-tpm-other-known-issues
- name: Decode Measured Boot logs to track PCR changes
href: /troubleshoot/windows-client/windows-security/decode-measured-boot-logs-to-track-pcr-changes
href: bitlocker/toc.yml
- name: Encrypted Hard Drive
href: encrypted-hard-drive.md
- name: Personal Data Encryption (PDE)