Microsoft has confirmed that the Windows 11 update KB5089549 fails to install on certain devices. The issue affects systems with critically low free space on the EFI System Partition (typically 10 MB or less). The update downloads and begins installing but fails during the restart phase at around 35–36% complete. Windows then rolls back the changes and displays error code 0x800f0922. Microsoft has provided two official workarounds: >Registry modification Open Command Prompt as Administrator and run the following command: reg add "HKLM\SYSTEM\CurrentControlSet\Control\Bfsvc" /v EspPaddingPercent /t REG_DWORD /d 0 /f Restart your computer and retry installing the update. >Known Issue Rollback: Microsoft is automatically deploying a server-side mitigation. Restarting your device multiple times can help activate it faster and allow the update to install successfully. A permanent fix will be included in a future cumulative update. Be sure to back up your registry or create a system restore point before making any registry changes.