Windows – Remote Desktop to Windows 7 without domain

1. Remote Desktop needs to be enabled (which it is if you are connecting to other computers from the same domain)
2. Check your router setting for port forwarding. For my Linksys router, it was under "Application & Games -> Port Range Forwarding". I had to forward 3389 to the client system trying to connect to the remote machine.
3. Finally, I had to put the port at the end of the IP. For example 192.168.1.110:3389.

You can search your registry for the Remote Desktop port number. The default is 3389. Open regedit and search for RDP-Tcp. Then look for PortNumber. You should see something like 0x00000d3d(3389).

Enter the domain in the User Name box as domain\username or username@domain.