Windows Update Fails: The Complete Fix

Published 2026 · 4 min read

Failed Windows updates usually come down to disk space, a corrupted update cache, or a stuck service.

1. Run the built-in troubleshooter

Settings → System → Troubleshoot → Windows Update finds and fixes most common problems automatically. Run it first.

2. Free up disk space

Updates need room to download and install. Free up 15-20% of your drive with Disk Cleanup → Clean up system files.

3. Clear the update cache

In an admin Command Prompt, stop the Windows Update service (net stop wuauserv), delete C:\Windows\SoftwareDistribution\Download, restart the service, then check for updates again.

4. When Windows undoes the update

That means install failed — often from space or a driver conflict. Disconnect extra USB devices and retry. If it keeps failing, search the specific error code online for the known fix.

Interactive version

Use the update fixer — tell it what happens and get the exact steps.