GPO information is stored in the Active Directory and replicated to all domain controllers.
The GPO is located at %SystemRoot%\SYSVOL\sysvol\<Domain Name>\Policies\\{GUID\}, where GUID is the Globally Unique IDentifier.
To locate the GUID of a GPO, open it in the Group Policy Editor, right-click the root, and press Properties. The GUID is the Unique name on the General tab.
To copy a GPO:
1. Create a new GPO in the target domain.
2. Determine the GUID of the source and target GPO.
3. Browse to %SystemRoot%\SYSVOL\sysvol\<Target Domain>\Policies\\{Target GUID\} and delete the contents of the Target GUID folder.
4. Copy the contents of %SystemRoot%\SYSVOL\sysvol\<Source Domain>\Policies\\{Source GUID\} to %SystemRoot%\SYSVOL\sysvol\<Target Domain>\Policies\\{Target GUID\}.
