Windows Updates Fail Clear the Windows Update cache (SoftwareDistribution + catroot2)

1) Run SFC and DISM to repair system files and the component store (low risk)​

• Open an elevated Command Prompt (Run as Administrator).
• Run: sfc /scannow — allow it to finish and note the result.
• If SFC reports problems or to be safe run: DISM /Online /Cleanup-Image /RestoreHealth — this can download replacement files and repair the component store. Re-run SFC afterward. Microsoft documents this exact sequence as the standard repair flow.

Why it helps: DISM repairs image corruption the installer depends on; SFC replaces protected system files. Many update rollbacks are caused by a damaged servicing pipeline that these tools can fix.

2) Clear the Windows Update cache (SoftwareDistribution + catroot2) (moderate risk)​

If downloads repeatedly reach 100% then the install rolls back, clear the cache:

• Open an elevated Command Prompt.
• Stop services:
  net stop wuauserv
  net stop bits
  net stop cryptsvc
• Rename folders (safer than deleting):
  ren %windir%\SoftwareDistribution SoftwareDistribution.old
  ren %windir%\System32\catroot2 catroot2.old
• Restart services:
  net start wuauserv
  net start bits
  net start cryptsvc
• Reboot and try Windows Update again.