I have a laptop using Windows XP2 which I use regularly at random networks from a fraternity house, in college classes, to my home. Needless to say, I am not sure how secure the networks are:

These programs run at system start up:
Total Security: Paid Norton Security Center
AntiVirus: Free AVG AntiVirus
Firewall: Free Zonelabs Zone Alarm

These programs run once a week:
AntiSpyware: Windows Defender Beta, LavaSoft AdAware, and Spybot Search & Destroy

I run Limewire for P2P now and then. I browse the internet with FireFox. I update regularly for windows, firefox and all of my security. I also game regularly online.

My question is: does this sound safe? What else can I do? I dont want too many intrusive programs taking up tons of RAM, but I would like to be secure, as this new laptop is my only computer. Are there any free programs out there for college kids that are good for protection? Or do I have enough stuff running to protect me?
Thanks all.