I really appreciate everyones comments but first of all, all the drawings are on drive "C" and I created them all (or a lot of them). Our IT people say it's probably a virus, but Autocad files are the only files I can't open. Autocad message says "drawing file is not valid" That's the only message I get. I'm just having a difficult time believing it's a virus. Hmm, Hmmm ?