In order to modify the RDP listening port, follow the steps mentioned below.
1) Run REGEDIT on your Server.
Start >> Run >> regedit and hit Enter
2) Export the following key: (Right click and export)
3) Edit the REG file and change the name of the key to something like:
4) In the REG file find
and change it to whatever port you want. (right click and modify)
5) Import the REG file back to the registry.
You can now connect to the new port by using the Windows Terminal Server client.
To Alter the Port on the client side:
1) Go to the Start menu and click on Run.
2) On the Run menu type mstsc and click Enter.
Note: To use RDP on computers with operating systems other than Windows XP/2003 you will first need to install the RDP client.
3) In the RDP window, in the Computer box, scroll to the computer name or IP to which you wish to connect.
4) Add a “:Port” (without the quotes) where “Port” is the decimal value of the destination port.
5) Press Connect.
Another method of connecting to a different port that default is to run the MSTSC command with the required command line parameters:
For example: MSTSC /v:192.168.0.191:3390
For more information : http://support.microsoft.com/kb/555031/en-us