what port does remote desktop use?
For either Windows XP or Vista, TCP port 3389 (which Remote Desktop uses) must be forwarded to the Remote Desktop PC. If you are setting up Web access, you also must forward TCP port 80 (or the non-default port you set) to the host computer.
If you are also setting up Web access to the Remote Desktop Connection, you must add TCP port 80 (or the port you choose for IIS if you changed from the default) to your Windows Firewall and any other third-party firewall.