Remember ONE THING and ONE THING ONLY. Always patch your FIREWALL FIRST, then your AV and lastly your OS. The way these viruses get into your machine is using badly configured firewalls or weak firewalls. If your firewall was good enough, it would've prevented that virus from infecting your system in the first place. Ok, even if your firewall fails, the AV is the next line of defence. Norton or McAffee normally dont allow .exes to change critical info like the bootsector information, etc... so I dont know how it allowed the virus script to run in the first place. The last defence was your OS. But in case of MS you can forget this line of defence