Run REGEDIT from Start>Run
Click on File, then select Connect Network Registry
Type the remote computer IP or host name in the Enter the object name to select and the click OK
If you don't have permission to access the remote computer, the logon screen will show up. Type the username and password for the remote computer. Then click OK.
Now, the remote computer is listed in the Registry Editor.
Browse to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server, in the right panel, seelct fDenyTSConnection (REG_DWORD). Change the value data from 1 (Remote Desktop disabled) to 0 (Remote Desktop enabled).
Close the registry