Quick fix: Force restart 3 times to enter Recovery Environment. Pick Troubleshoot → Advanced options → Startup Repair. Wait. If unsuccessful: try Command Prompt → run bootrec /fixmbr, bootrec /fixboot, bootrec /scanos, bootrec /rebuildbcd. Reboot. For chronic: chkdsk /f /r C: for disk repair (may take hours).

Power outages can corrupt: file system, boot configuration, BCD, registry. Windows fails to boot. Repair via Recovery Environment’s tools. Disk repair may be needed for filesystem corruption.

Symptom: Fix Windows 11 boot failure after a power outage without reinstalling.
Affects: Windows 11.
Fix time: ~1 hour.

What causes this

Power outage during write operation can corrupt:

File system metadata (NTFS).
Boot Configuration Data (BCD).
Registry (mid-write).
Specific system files.
Hardware (rare; usually data only).

Method 1: Startup Repair

The standard route.

Force restart 3 times: hold power button to shut down, then power on; repeat.
4th boot: Windows enters Recovery Environment.
Pick Troubleshoot → Advanced options → Startup Repair.
Pick your account. Enter password.
Startup Repair runs. Detects common boot issues automatically.
Reports: “Startup repair couldn’t repair your PC” if issue not auto-fixable.
Or: “Windows successfully repaired” — reboots.
For chronic: re-run Startup Repair after each boot attempt. Sometimes succeeds on second try.

This is the automatic route.

Method 2: Manually repair via Command Prompt

For when Startup Repair fails.

Recovery Environment → Troubleshoot → Advanced options → Command Prompt.
Identify Windows drive (drive letters may differ in Recovery):
```
diskpart
list vol
exit
```

Run boot repairs:

bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcd

For Access Denied on /fixboot:
```
bcdboot C:\Windows /s C: /f UEFI
```
(Adjust drive letter.)
Run filesystem check:
```
chkdsk C: /f /r
```
Takes 1-4 hours. Repairs filesystem corruption.

Run SFC + DISM for system file repair:

sfc /scannow /offbootdir=C:\ /offwindir=C:\Windows
dism /image:C:\ /cleanup-image /restorehealth

Exit Command Prompt. Restart.

This is the manual repair.

Method 3: System Restore if previous boot worked

For rolling back recent changes.

Recovery Environment → Troubleshoot → Advanced options → System Restore.
Pick a restore point from before the power outage.
Confirm. System Restore replays state.
Reboot.
If System Restore succeeds: Windows boots.
For chronic boot issues even after restore: continue to other methods.
For long-term: configure System Restore to keep more restore points (Control Panel → System Properties → System Protection → Configure).

This is the rollback route.

How to verify the fix worked

Windows boots to login / desktop.
No recurring boot failures.
Files / apps intact.
Event Viewer post-boot shows clean startup.

If none of these work

If still won’t boot: Disk hardware failure: power outage may have damaged drive. Test with SMART tool from Linux Live USB. For UEFI corruption: BIOS may need reset. For BitLocker: have recovery key ready. For chronic boot fail: clean install with backup. For data preservation: boot Linux Live USB, copy data off C: to external drive first. For Surface devices: Surface Recovery Image USB. For dual-boot: power outage may have broken bootloader for both OSes. Repair from Linux Live USB. For chronic power outages: invest in UPS (Uninterruptible Power Supply).

Bottom line: Force restart 3x to Recovery → Startup Repair. If fails: Command Prompt → bootrec commands + chkdsk + SFC. System Restore to rollback. UPS prevents future outage damage.