Hmm..., well some modems even have a firewall as well, but to further assert what others have said, you can have 15 firewalls on, and it won't hurt other than maybe slow down the 'net a bit. I would say shut off the Windows Firewall, 'cause it stops about as much as swiss cheese would. And get a ZoneAlarm firewall, comes either with their standard Anti-Virus package, or a little better buy would be the whole Pro suite, great programs.