Enabling Remote Desktop using regedit, follow these steps:

1. Run REGEDIT from Start>Run
2. Click on File, then select Connect Network Registry
3. Type the remote computer IP or host name in the Enter the object name to select and the click OK.

4. 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.

5. Now, the remote computer is listed in the Registry Editor.

6. 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).

7. Close the regeidt.

8. Try to connect now that machine using the RDP.