CompuServe Messages

Help! I am having a problem with "Atdisk" not starting in Windows NT. What is it? What does it mean? How do I fix it? NT starts and appears to be functioning ok, except a program I need to run says "Bad Display Configuration". I have an ATI Graphics Pro Turbo in it. It looks good. 24Bit 800×600 @ 70 Hz. It used to work two months ago. I haven't run NT since then. Since that time, I have had a controller card go bad. It has been replaced with a different one. I have tried two different controller cards. One at least works, the other says HD failure. They are both good on another system. All help appreciated. Thanks, Dennis