How can I change the listening port for Remote Desktop Connection?
For additional security, you can change the port that Remote Desktop Connection uses (or "listens on"), instead of using the standard port 3389. When you log on, type the remote computer name, followed by a colon and the desired port (for example, Computer1:3390). For instructions about making the change permanent, go to How to change the listening port for Remote Desktop on the Microsoft Help and Support Web site.
Note: This information provided by Microsoft.