Active Directory Lookup
Group Policy processing requires Active Directory. The Group Policy service reads and updates information stored in Active Directory. The absence of Active Directory (or a domain controller) prevents Group Policy from applying to the computer or user.
Discover user and computer forests
The Group Policy service failed to obtain a list of domains in the forest. Group Policy processing stopped because the Group Policy service cannot determine if the user and computer belong to the same forest.
To correct user and computer forest discovery:
Find the error code displayed in the error event. The error code appears on the Details tab of the error event. The error code and error description fields may help identify the reason for the failure.
Ensure domain controllers are accessible in the domain that hosts the computer object.
Disjoin and join the computer to the domain. Then log on with the same user account that experienced the problem.
Use Active Directory troubleshooting procedures to further diagnose the problem.