Fix Windows Update when it fails or gets stuck

Most Windows Update failures come down to a pending restart, a full disk, or damaged update files. Work down this list and stop as soon as updates install.

Symptoms

• Settings › Windows Update shows “Install error” or “Download error” with a code such as 0x80070002, 0x80070070, 0x800f0922 or 0x80073712.
• An update sits at the same percentage for over an hour.
• The same update fails, rolls back, and offers itself again after every restart.

Common causes

Code	What it usually means
0x80070070	Not enough free disk space
0x80070002	Update files are missing or incomplete; often fixed by retrying after a restart
0x800f0922	Couldn’t reach the update servers (often a VPN), or a small system partition is full
0x80073712	The Windows component store is damaged and needs repair

Fix

1. Restart, then retry

Restart from Start › Power › Restart (not Shut down, which can skip pending work). Then open Settings › Windows Update and click Check for updates or Retry.

2. Free up disk space

You need roughly 20 GB free on drive C: for feature updates and several GB for monthly ones.

1. Open Settings › System › Storage.
2. Select Temporary files, tick Windows Update Cleanup and Temporary files, then click Remove files.
3. Empty the Recycle Bin and move large personal files to OneDrive.

3. Disconnect from VPN

Sign out of any VPN client, restart, and retry. Some VPNs block the update servers.

4. Run the Windows Update troubleshooter

• Windows 11: open the Get Help app and search for Windows Update troubleshooter.
• Windows 10: Settings › Update & Security › Troubleshoot › Additional troubleshooters › Windows Update.

5. Repair Windows system files

This is safe but needs administrator rights and takes 10–30 minutes.

1. Right-click Start and choose Terminal (Admin) or Command Prompt (Admin).
2. Run:

   DISM.exe /Online /Cleanup-Image /RestoreHealth

3. When it finishes, run:

   sfc /scannow

4. Restart and try Windows Update again.

If that didn’t work

• Install the update manually. Note the KB number shown in Windows Update (for example KB5012345), search for it in the Microsoft Update Catalog, download the version matching your system (x64 for most PCs) and run it.
• For IT staff: reset the update cache from an elevated prompt. This forces Windows to re-download everything, so expect a slower next update.

  net stop wuauserv
  net stop cryptSvc
  net stop bits
  net stop msiserver
  ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
  ren C:\Windows\System32\catroot2 catroot2.old
  net start wuauserv
  net start cryptSvc
  net start bits
  net start msiserver

When to call us

• The PC is on Windows 10. Support ended on October 14, 2025, so it only receives updates through the Extended Security Updates program. See Windows 10 end of support: your options.
• Updates have failed for more than a month: the PC is missing security fixes.
• An update left the PC unable to start, or stuck in a restart loop.