I have a 18mo old Dell Dimension 2350 that has virus problems,so i need to reformat ,when i go to reinstall XP it starts the setup process,but i get (Stop:c0000221unknownHardError\systemroot\system32\ntd77.d77) before the setup screen that says (to setup  windows Xp now, press enter)40 gig Hard drive,i have nothing connected except mouse and keyboard,non USB.Any Ideas Thanks