Upon bootup today ADT3.3 won't load. Graphic driver files missing. I go to my applications partition, ADT directory and about 3/4 of the autocad files and all of the ADT subdirectories are GONE! Disk search for ADT files finds nothing! No viruses. Win2000Pro on clean HP workstation. Nothing fluky like this ever before. Other apps and files seem fine. ADT 3.3 with updates and patches installed. What the heck is up with that?