Microsoft has resolved an issue that caused Windows 11 KB5089549 installations to fail with 0x800f0922 errors on devices with low EFI System Partition free space. The fix is included in KB5089573 and later, with Known Issue Rollback and Group Policy available as workarounds for users and enterprise admins who have not yet installed the latest update. #KB5089549 #KB5089573 #Windows11
Keypoints
- Microsoft fixed a Windows 11 update installation issue tied to low EFI System Partition space.
- Affected devices could fail with 0x800f0922 and roll back during reboot at 35–36% completion.
- The problem was resolved in the May 26, 2026 KB5089573 preview update and later releases.
- Users can also mitigate the issue with Known Issue Rollback if they skip the optional update.
- Enterprise admins can apply a Group Policy workaround, and Microsoft has published deployment guidance.