diff --git a/windows/security/threat-protection/microsoft-defender-atp/oldTOC.txt b/windows/security/threat-protection/microsoft-defender-atp/oldTOC.md
similarity index 100%
rename from windows/security/threat-protection/microsoft-defender-atp/oldTOC.txt
rename to windows/security/threat-protection/microsoft-defender-atp/oldTOC.md