WARNING: Following the procedure in this post will result in losing all custom changes to the default policies. – Make a backup / duplication with GPMC just in case.
The procedure below will restore the GPOs to almost its original state. Se more information about this at Microsofts KB833783 article
Microsoft recommends you use GPMC to back up and restore all GPOs in your environment. The Dcgpofix tool is a disaster-recovery tool that will restore your environment to a functional state only. It is best not to use it as a replacement for a backup strategy using GPMC. It is best to use the Dcgpofix tool only when a GPO back up for the Default Domain Policy and Default Domain Controller Policy does not exist.
PS: Backup of GPOs does not include Links, Security Filter and ACLs. Therefore it is a good idea to document these when doing backup – Just save the settings report to a html file from the Group Policy Management Console.
Procedure for reseting the default policyes:
Log on as a domain administrator to a domain controller (DC).
Open a command prompt
Reset the GPO(s)
To reset the Domain GPO, type dcgpofix /target:Domain
To reset the Default DC GPO, type dcgpofix /target:DC
To reset both the Domain and Default Domain Controller GPOs, type dcgpofix /target:both
- After you enter the appropriate command, enter Y to both prompts.
- Close the command prompt