SOLUTION TO Windows Backup Error Code 0x810000027
The backup application could not start due to an internal error: Access denied. Check system configuration.

After about 4 hours of reading and trying new fixes for errors 0x810000027, I finally managed to get Windows Backup to change settings and start.

This is all-inclusive in case more things are broken for you.

1. Make sure the following services are set to Stopped
Block Level Backup Engine Service
Microsoft Software Shadow Copy
Volume Shadow Copy
Windows Backup (also make sure the Backup & Restore window is closed or this will auto-restart)
2. In Explorer, Gain Access to the System Volume Information folder (right click, properties, security, advanced, owner tab, Edit button, click your user name & check Replace owner on subcontainers and objects, OK, Yes, OK, OK, OK.
3. Using a 3rd party tool (Eraser) - delete System Volume Information\Windows Backup and System Volume Information\WindowsImageBackup,
4. Make sure the services in step #1 are started again and set to automatic for good measure.
5. Launch Windows Backup & Restore

Click change settings, and voila the backup is working!.

Post a comment if this worked or did not work for you.