Microsoft posted a KB article to explain how to resolve an issue when a Windows Server 2012 Remote Desktop Virtualization Host is added to a domain and the default domain policy is applied, the option to select a physical GPU used for Remote FX (within Hyper-V settings) is unavailable.
This is caused because the Users group has been removed from he “Allow log on locally” policy. RemoteFX uses a system account called RDV Graphics Service which is a member of Users.
The fix is to ensure that:
- Users has the Allow Log On Locally right and
- Users is not added to the Deny Logon Locally policy.
Note that this issue is fixed in WS2012 R2.