servicing C:\Windows\servicing

Component-Based Servicing folder: package manifests, servicing sessions and servicing stack versions used to install Windows updates.

Updated on 12 November 2026 By AltF4 Formation

What it’s for

C:\Windows\servicing is the folder of the Windows servicing stack (Component-Based Servicing, CBS), the component that installs updates. It keeps metadata about installed packages and the state of servicing operations, while the files themselves live in the WinSxS component store. Its log is C:\Windows\Logs\CBS\CBS.log.

What it contains

Packages: manifests (.mum) and catalogs (.cat) of installed packages and updates.
Sessions: traces of servicing sessions (installs, uninstalls).
Version: one subfolder per servicing stack version, for example 10.0.14393.1051. Microsoft notes that this folder is created automatically when a servicing stack update is installed.
Version only grows when a servicing stack update is installed.

Risks and best practices

Any tampering (a file deleted, moved or edited) is paid for in failed update installations, “corrupted component” errors, or even a system that cannot be repaired. The files are owned by TrustedInstaller, so do not take ownership of the folder.
A new Version subfolder after an update is normal. Some third-party backup products flag it with a harmless warning.
To free disk space, use Disk Cleanup or DISM, never manual deletion.
To troubleshoot, read CBS.log, then run sfc /scannow and DISM /Online /Cleanup-Image /RestoreHealth.

Useful commands

# Read-only: folder contents (as administrator)
Get-ChildItem "$env:windir\servicing" -Force | Select-Object Name, LastWriteTime

# Known servicing stack packages (sample)
Get-WindowsPackage -Online | Select-Object -First 10 PackageName, PackageState

# Analyze the component store (as administrator)
DISM /Online /Cleanup-Image /AnalyzeComponentStore

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