Windows Update

Where Windows Update keeps its logs

Windows Update logs to C:\Windows\Logs\WindowsUpdate\ on Windows. 1 other Windows log location is recorded below.

Paths are printed exactly as Windows Update writes them. Environment variables like %LOCALAPPDATA% and $XDG_STATE_HOME are never expanded, so a path can be pasted straight into a shell. Where a path differs between installer types or shipping flavours, each one is racked as its own card below - why that happens.

Finding your way around Windows.

How to turn on debug logging for Windows Update

1. Nothing to switch on: Windows Update writes ETW trace logs all the time.
2. To flush current traces first, run Get-WindowsUpdateLog -ForceFlush in an admin PowerShell. It stops the Update Orchestrator and Windows Update services.

How to collect Windows Update logs

1. Run Get-WindowsUpdateLog in PowerShell. It merges the .etl traces into WindowsUpdate.log on your Desktop.
2. Run it again to refresh. The file is a snapshot and does not update itself.
3. To include the Update Orchestrator and UX logs, run Get-WindowsUpdateLog -IncludeAllLogs. It writes WindowsUpdate.log, USO.log and UX.log into a Desktop folder.
4. Add -LogPath to write the file somewhere else.
5. Feature update failures: run SetupDiag and collect %windir%\Logs\SetupDiag\SetupDiagResults.xml.