I think WinXP comes with a firewall. It's cheaper than ZoneAlarm and requires no configuration. It'll serve as a basic firewall for you until you upgrade to a hardware firewall later on down the road. I've not used WinXP Home so I'm not sure if that has the firewall; I have a TabletPC and they come with Pro. To turn on the built-in firewall, find "network connections" in the control panel, then right-click the network connection you're using (ethernet or wireless?),select "properties." Under the "Advanced" tab you'll see the Firewall option. If you want to configure it, just click the "Advanced" button after you've activated the firewall. Hope that helps.
