He can leave the Windows Firewall on. In fact, Leo doesn't recommend the full ESET offering of desktop security products. Just get the antivirus, and turn on the Windows Firewall. Since Justin may be using college campus internet, the firewall will protect Justin from network viruses or worms propagating on his system. The Windows Firewall isn't real powerful, but it's good enough and will protect him against worms coming from within the network he's on. (Disclaimer: ESET is a sponsor).