Remote Desktop Protocol (RDP) allows remote connections to the PC using remote computer’s IP-address or name. It has a great variety of settings which can help with configuring RDP for slow connections or to make it more secure. By default, the server listens on TCP port 3389. That’s why the basic info to connect to the remote PC is its IP-address(name). To provide stronger security you may want to change the default port, so that attackers will not be able to connect via default port.
To change port number for RDP in Windows XP:
1. Navigate to the following key in the registry from left pane:
1.1. Start > Run > type in: regedit – press Enter.
2. Double click on PortNumber entry, then click on Decimal, type the new port number and then click Ok. Close Registry Editor.
NOTE: When you try to connect to the remote computer using Remote Desktop Connection, you’ll need to specify new port number.
Make sure the firewall is opened for this new port.