I recently had my CD driver replaced. It worked fine for a few weeks, then :-/, but now when I start up I get this message:"unable to detect ATAPI IDE CD ROM---device driver not loaded." What's up with this? Do I need to replace the driver again? I have defragmented, scanned the disc, and ran the virus scan none of this helped!? I have a Compaq 5451 and the CD drive I just put in is AOpen-52X and nero burning ROM

If you can see text when te computer first boots, see if there is anything that says ATAPI or CD or anything like that. If it is there, it means that at least eh computer is recognising that there is a CD drive there.

Also, if you don't mind my asking, how much did you pay for the new CD drive? I went through a few different cheap CD drives before I decided to get a little more expensive one. The cheap ones are usually very low quality. When you say it worked fine at first, it makes me think maybe you got a CD drive that was cheaply made.

Also, is it still under warranty? If it is, see if you can get the manufacturer to diagnose the problem.