sasser virus

sir/madam
i have an pc at my res which is having the following p4/256mb/2.8Ghz/intel 265GBF M/B and loaded with win2k,office2k,service pack4,6MB patch for Blaster virus and other windows updates from the site(Microsoft site)and norton 2004 with latest updates to my pc the problem is when ever i connect to internet it will say that “windows had found error in the file system it will restart in 60sec” and it do the same. Even i have downloaded an patch for that SASSER virus but its doing the same please help out in this isses