The one built into xp is fine.
Guess what? it's just as good.
Guess what? it's just as good.
Not really as it only filters incoming packets. Say for example your PC acquired a piece of spyware due to a security issue in the browser you used. The firewall built into XP would not alert you to the spyware sending info outwards but sygate(for example) would alert you straight away as that programme is not on its allowed list of network traffic.