Remote desktop (RDP) is a great way to remotely access Windows-based desktops and servers. Although security through obscurity is not a reliable method of securing anything, changing a service's listening port can be an effective way to reduce random break-in attempts from botnets. This method will work for Windows XP or Vista.
The standard port for RDP is 3389, and you can determine an unused port by checking this list of common port numbers. I would recommend using an unused port higher than 1024. You can change the RDP port by following these steps:
- Enter the Windows' registry by clicking on the Start Menu, Run, and typing: regedit.exe
- Locate and then click the following registry subkey:
- On the Edit menu, click Modify, and then click Decimal
- Type the new port number and click OK, then close the registry editor.
For more information, see Microsoft's Knowledge Base article about changing the remote desktop listening port.