ZoneAlarm's firewall will offer more protection, unles pccillin offers a two way firewall in the latest version. Only run ONE though. So if you like ZoneAlarm, disable pccillins. If you like pccillins, disable zonealarm. A really lightweight firewall is LookNStop or Kerio 2.1.5, or Ghostwall for that matter. They are all feather light, and use under 7MB of memory