UDP ports 1716 for the game 1717 for the gamequery 1718 for the master server query 8777 for the standard UT query 27900 for GameSpy TCP Ports 20045 and 20046 for the Auth server 20025 TCP for the new AA Browser (MBS)
Click the Security Center link near the bottom left of the page.
Click the Windows Firewall link near the bottom right of the page.
Remove the checkmark from the Don't allow exceptions checkbox.
We will list a series of lines here that will show you exactly how to setup Windows XP Firewall's firewall for Americas Army. Go ahead and enter the settings shown below into the Add Port menu.
You should see another page of settings below that need to be added to Windows XP Firewall. Open up a new Add Port page and enter those settings.