HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Backup\Server

Disallow run-once backups
- HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Backup\Server\NoRunNowBackup
Disallow optical media as backup target
- HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Backup\Server\NoBackupToOptical
Disallow network as backup target
- HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Backup\Server\NoBackupToNetwork
Disallow locally attached storage as backup target
- HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Backup\Server\NoBackupToDisk
Allow only system backup
- HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\Backup\Server\OnlySystemBackup