Symptoms
When you automatically prepare an existing domain for Windows Server 2012 by using Windows Server 2012 Server Manager or the Install-AddsDomainController Windows PowerShell cmdlet, Group Policy preparation is not performed. Additionally, the following output is displayed very briefly when you use Install-AddsDomainController:
Adprep successfully updated the forest-wide information.
Adprep successfully updated the domain-wide information.
The new cross domain planning functionality for Group Policy, RSOP Planning Mode, requires file system and Active Directory Domain Services permissions to be updated for existing Group Policy Objects (GPOs).
Note This output is not visible when you install Active Directory Domain Services (AD DS) by using Server Manager, and the output is not logged.
Cause
This behavior is by design. The automated remote domain preparation capabilities that are added in Windows Server 2012 do not alter the Group Policy preparation (Gpprep) behavior that occurred in earlier operating systems.
Gpprep adds cross-domain planning functionality for Group Policy and Resultant Set of Policy (RSoP) planning mode. This requires updating the file system in SYSVOL and Active Directory permissions for existing group policies. If the environment already contains custom or delegated permissions that were put in place manually by administrators, Gpprep triggers replication of all Group Policy files in SYSVOL and may deny RSOP functionality to delegated users until their permissions are re-created by administrators.
Resolution
Domain administrators must run adprep.exe /domainprep /gpprep manually, just as they had to do in Windows Server 2003, Windows Server 2008, and Windows Server 2008 R2.
More Information
Administrators should run Gpprep only one time in the history of a domain. They should not run Gpprep every time that an upgrade occurs. Gpprep was introduced in Windows Server 2003.
The Adprep.exe tool is included on the Windows Server 2012 media at \support\adprep. This version of Adprep.exe supports remote preparation and does not have to run on the infrastructure master operations master (also known as flexible single master operations or FSMO) role, as it did in previous server operating systems.
For more information about legacy Adprep.exe commands, go to the following Microsoft TechNet website:
