How to remotely enable Remote Desktop

If you need to enable the remote desktop, you can set fDenyTSConnections to 0

HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server

The same job can be done through GPO with "Allow users to connect remotely using Terminal Services"

http://technet2.microsoft.com/windowsserver/en/library/608fb22b-5138-4f4b-873d-4aa8fc23cd641033.mspx?mfr=true