KB5072033 Fails With Error 0x800f0991 on Windows 11, Users Find Early Fixes

Windows 11 users report a growing number of installation failures with update KB5072033, often ending with error 0x800f0991, as users on Reddit report. Many noticed that the KB5072033-x64.wim file delivered through Windows Update appears significantly smaller than the version from the Microsoft Update Catalog, which sparked suspicion that the package might be incomplete.

Attempts to fix the issue with service restarts, DISM, or SFC scans don’t seem to help, and the update continues to fail for affected users. Until Microsoft acknowledges the problem, two workarounds show promising results.

How to fix the KB5072033 install error

Some users restore Windows Update components through a built in repair option.

1. Open Start and go to Settings
2. Select Windows Update
3. Open Update history
   
   
4. Choose Recovery
   
5. Under Fix problems using Windows Update, click Reinstall now

Windows repairs the update components and keeps all personal files intact. Several users report that KB5072033 installs normally afterward.

A more advanced approach involves manually handling the MSU package.

1. Download the update MSU from the Microsoft Update Catalog
2. Extract the MSU
3. Uninstall the failed update using DISM
4. Restart the device
5. Reinstall the update using the original MSU package

This workaround helped some users, but results vary.

Should you install KB5072033 right now?

Given the size mismatch in the WIM file and the repeated 0x800f0991 install failures, many users prefer to hold off until Microsoft confirms or fixes the issue. KB5072033 remains unacknowledged at the time of writing, so pausing updates might avoid repeated failures.

On the other hand, KB5072033 did fix File Explorer and Ask Copilot issues, so if you’re having those issues, you might want to give this update a try. Did you have any issues with the update? Let us know in the comments.