Run CMD as Administrator and run “del C:\Windows\security\database\secedit.sdb”
After deleting the security database you have also to delete some registry settings. Be carefull!
Run in the same cmd “Regedit” and go to HKLM, Software, Microsoft, Windows, Current Version and delete the key Group Policy
after that type in gpupdate /force /boot
Your computer should now be cleared of all domain policies.