My DVD-RW drive has stopped recognizing CDs, but it can read and write DVDs flawlessly.
Is this a software or a hardware problem? How can I fix thus?
I had much the same issue with my Lite-on DVD writer. Oddly enough it seemed to happen directly after a windowsXP update. After some research on the 'net (much like you are doing now) I found others with the same issue, remedied by flashing the firmware on my DVD drive. I found some good tips and the correct firmware at The Firmware Page If you can tell me/us the make/model of your DVD drive, then maybe some more specific help can find its way to you.