On the target machine, make sure that Port 3389 is not being blocked by a firewall. If you are using Windows Firewall, go to the Windows Firewall control panel, verify that “Don’t Allow Exceptions” is not checked under the “General” tab, then click on the “Exceptions” tab and make sure there is a checkmark beside “Remote Desktop”.
You can also make sure that a program is running to accept incoming remote desktop connections by bringing up a command prompt (Start -> Run -> “cmd”) and entering the following command:
netstat -an | find “3389”
If all is well, you should see the following line returned:
TCP 0.0.0.0:3389 0.0.0.0:0 LISTENING