i got a virus that's been screwing up my computer, tried everything to get rid of it. Couldn't. So i've decided to format my hard drive. I think i'm supposed to do it from DOS and that i need a boot disk, but i have no idea how to start up in DOS and i recently had a new hard drive installed and now my A: drive isn't showing up so i can't create a boot disk. My OS is Windows XP. Please help...your my only hope