I have been using the built-in WinXP firewall, but understand the need for something more robust (at least a 2-way firewall). We're currently running Avast (paid) virus software and Adaware (paid) for spy crud. I've tried a few firewalls that I'm not too thrilled with. I thought ZoneAlarm too picky or nervous it seems and I recently tried another one, COMODO, that also seemed way too neurotic and never did seem to 'learn' our system. So, looking for something that is not very intrusive...install and let it go w/o being alerted to every single little thing going on. I want a small memory footprint, so McAfee and Norton are out So what do some of you rely on that you're pleased with?