Free home PC prophylactic products

[ChipWrecked]

For firewall, I use the one built in to MS XP Pro and it's fine for me. Link goes to ZoneAlarm's checklist for their free product for non-XP users.

I use the free home version of Avast
for anti-virus and I highly recommend it. It dectected every variant of the recent Blaster worm that came to my box.