Originally posted by Spork 2.0
Depends, for most people merely running the firewall that comes with XP SP2 and a router (which have internal firewalls) is enough. However, if you're like me and like to see everything that is going on with your network connections a software firewall would be a good choice, I myself use Kerio. There are dozens of free firewalls out their, while not many are very good, there are a couple of gems. If you are really concerned about network security give this site a look see.
I disagree about using software firewalls. Their only use is stopping something from getting out. However if something is on your PC, since your using windows your screwed. I do however run better hardware firewalls than most other people *cough* Cisco *cough*.
If you sure about whats on your PC and are careful their's no reason to use a software firewall. One exclusion however is connecting to unsecure wireless networks.