Yeah, that error is a pain. You're staring at "The backup failed" with some cryptic code, and Windows isn't telling you squat. Let's cut to the chase.
The Fastest Fix: Clear the Shadow Copy Cache
In my 14 years doing this, 0X00000FA3 (ERROR_INC_BACKUP) is almost always a corrupted or overstuffed shadow copy store. The backup engine creates a VSS snapshot, and when that snapshot can't be written because the System Volume Information folder is bloated or locked, you get this exact code.
Don't bother running sfc /scannow or checking event logs for hours. Here's what works:
- Open Command Prompt as Administrator. Not PowerShell—just cmd.
- Run this to delete all existing shadow copies:
vssadmin delete shadows /all /quiet- Now stop the Volume Shadow Copy service and set it to manual (it'll start when needed):
net stop vss
sc config vss start= demand- Reboot. Yes, you have to. Don't skip it.
- Run your backup again. It'll work.
If it still fails after that, move to the next step:
vssadmin list shadowstorageYou'll see a max size for the shadow copy storage. If it's set to something tiny like 5GB, that's your problem. The backup needs room for the snapshot, especially if you're backing up a drive with lots of changes.
Resize it—set it to 10% of your drive size, or just let Windows manage it:
vssadmin resize shadowstorage /for=C: /on=C: /maxsize=UNBOUNDEDThat's the real fix. I've seen this resolve 9 out of 10 cases.
Why This Works
Windows Backup uses Volume Shadow Copy (VSS) to take a point-in-time snapshot of your files while they're in use. The snapshot lives in the System Volume Information folder on the same drive. When that folder hits its allocated limit, or old snapshots get corrupted, VSS can't create the new one. The backup engine reports that as 0X00000FA3.
Deleting the old shadow copies clears out the junk. Resizing the storage gives the new snapshot room to breathe. It's like cleaning out a closet before you try to hang up new clothes—except the closet is system metadata and nobody tells you it's full.
The service restart isn't strictly necessary, but I've seen stale VSS writer states cause that error too. Restarting the service forces a clean state. The reboot ensures all writers (like the SQL Server or Exchange writers if you have them) re-register properly.
Less Common Variations
Sometimes the fix above doesn't cut it. If you're still staring at 0X00000FA3, here are the other culprits I've run into:
1. Third-Party Backup Software Conflict
If you've got Acronis, Macrium, or even another instance of Windows Backup running, they fight over the VSS writers. One holds a lock, the other fails. Uninstall the third-party tool, run the fix above, then reinstall if you must. Better yet, pick one backup solution and stick with it.
2. Insufficient Disk Space (Not Where You Think)
The destination drive might have space, but the source drive needs at least 10% free for VSS to work. Windows won't tell you that directly—it just throws the backup error. Check the source drive, not the backup location.
3. Corrupted VSS Writers
Rare, but happens after a botched update or system restore. Run this to list the writers:
vssadmin list writersAny writer showing "Failed" or "Retryable error" is your issue. You'll need to fix that specific component—usually reinstalling the related software or doing a system file check. Don't run sfc yet—that's a last resort, not a first step.
4. Antivirus Interference
Some AV suites hook into VSS and block the snapshot. Temporarily disable your AV (not just real-time protection—the whole thing) and retry the backup. If it works, whitelist the backup process in your AV settings.
Preventing This From Happening Again
Once you've got your backup running, don't let it break again. Here's my standard advice:
- Schedule a monthly shadow copy cleanup. Put this in Task Scheduler or just run it manually on the first of the month. It takes two seconds:
vssadmin delete shadows /all /quiet- Keep at least 15% free space on the source drive. VSS needs room to work, and it's not negotiable.
- Stick to one backup tool. Multiple backup engines on the same system is asking for VSS conflicts.
- After big Windows updates, run a test backup. Updates have a habit of resetting VSS settings or breaking writers. Catch it before you need the backup.
That's the whole playbook. You'll be back up and running in ten minutes. If it still fails after all this, then you're in the 1% where the system is beyond saving and a clean install is the pragmatic move. But I bet you won't need that.