A Windows 11 update stuck at 0%, 99%, or 100% is not always frozen. Windows may still be downloading, verifying a package, preparing a rollback path, or servicing protected files after a restart. The correct fix depends on the stage shown in Windows Update and the error code in Update history. This guide starts with reversible checks, then moves to the Windows Update cache, Microsoft repair commands, error-specific actions, and Windows 11’s built-in repair reinstall. It does not require a registry cleaner, driver pack, unofficial ISO, or third-party “PC repair” program. Quick Answer Keep the PC powered, wait if Windows is still showing activity, and restart normally when the desktop is available. Then check the connection and free storage, run Settings → System → Troubleshoot → Other troubleshooters → Windows Update → Run , and note the failed update’s error code. If it still fails, clear the Windows Update cache, run DISM followed by SFC, and use Fix problems using Windows...