Hi,
Actually, the old "Copy Profile" method is depricated and NOT supported since Win2k8 R2 has came out. The supported way to copy the settings to the default profile is by using Sysprep.
What I suggets, from my experience, is the following:
1. Make all necessary changes to the OS (GUI, GPO etc.)
2. Run sysprep: C:\Windows\System32\sysprep\sysprep.exe /generalize /oobe /reboot /unattend:CopyProfile.xml
Where CopyProfile.xml is an XML file that (in this case) should be located under the sysprep directory. In this XML file, you can populate all kinds of XML tags. One of them is the <CopyProfile> tag. (<CopyProfile> true </CopyProfile>)
This XML is build with the Windows System Image Manager.
3. After sysprep has finished, you get the OS after the Administrator profile has been copied properly. This is the only supported way by Microsoft to copy the Administrator profile to the Default Profile.
Good luck!