You can enable remote desktop on a remote machine via it’s registry by following the instructions below:

1) Open registry, connect to the machine you wish to enable RDP. (File and connect remote registry)
2) Expand HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server
3) Amend the value key fDenyTSConnection (REG_DWORD) from 1 (Disabled) to 0 (Enabled)
4) Exit registry editor