Clear Windows Update Cache

Windows downloads update files into C:\Windows\SoftwareDistribution\Download. If an update fails or loops, those gigabytes stay stuck there and Windows Update cannot progress until the folder is cleared.

Short answer: open an admin Command Prompt, run net stop wuauserv and net stop bits, empty C:\Windows\SoftwareDistribution\Download, then run net start wuauserv and net start bits.

Stopping the Windows Update service

You cannot delete inside SoftwareDistribution while Windows Update is running — the files are locked by the service.

1. press Start, type cmd
2. right-click Command Prompt, choose Run as administrator
3. in the terminal, run:
   • net stop wuauserv
   • net stop bits
4. wait for both "stopped successfully" messages — leave the window open

Both services must stop: wuauserv is Windows Update, bits is the Background Intelligent Transfer Service that actually downloads update payloads.

Emptying SoftwareDistribution\Download

Now the files are unlocked and safe to delete.

1. open File Explorer
2. navigate to C:\Windows\SoftwareDistribution\Download
3. press Ctrl + A to select everything inside
4. press Delete (click Continue if prompted for admin permission)
5. confirm the folder is empty — do not delete SoftwareDistribution itself, only the contents of its Download subfolder
6. return to the admin Command Prompt and run:
   • net start wuauserv
   • net start bits
7. close the Command Prompt
8. open Settings > Windows Update and click Check for updates — Windows will redownload the update cleanly

If the update still fails after this, the underlying cause is usually a corrupted system file (sfc /scannow) or not enough free disk space (often needs 15–20 GB headroom for a feature update).

Better next routes

For the broader Windows cleanup picture, continue with How to Free Up Space on C Drive Windows 11 Natively.

For remaining post-update leftovers, read How to Delete the Windows.old Folder (If Disk Cleanup Fails).