Changing the Remote Desktop Port. If you have two computers on a network you want to remote control, you can use a different port for the second computer. Forward port 3389 on your router to the first computer for standard Remote Desktop access. Select a different port for the second computer, for example, 3390. Forward port 3390 on the router to port 3389 on the second computer. When you launch Remote Desktop from the remote location, type your network IP address to access the first computer or type your network IP address followed by a colon and the port number you selected for the second computer, for example, 74:125:228.177:3390.