Remotely enable Remote Desktop Protocol to a target server.

Requirements: Local admin or domain admin privilege on the target server.
Use the registry editor to connect to the remote registry of the target server.
Find the following key:
"HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server"
Set the key fDenyTSConnection, where 1=disabled, and 0=enabled.
Then make sure the user account for connecting is in the local  remote desktop users group on the target server and you can connect in.