Before we can open ports for ABC, we need to figure out what ports ABC is using. Here is a brief walkthrough on how to do that. Go ahead and open up ABC.
Click File in the menu at the top of the program. Then click Preferences in the list that drops down.
In the menu on the left hand side of your screen, click the Network link. On this page you should see a Port box. You can change the port number that ABC is using if you like. The number that is in that Port box is the port that you will have to open. Please enter the number that was in that box below.
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 ABC. Go ahead and enter the settings shown below into the Add Port menu.