Safechav is right..... The first things that usually fail on CD drives is the recognition of blank or recordable media. Blank discs are usually firs to fail, next will be the ability to read CD-RW discs that have media or data on them, then CD-R's that have media or data on them.

This also applies to domestic CD players also - my hifi sometimes completely refuses to recognise albums I have burned to CD-R - it just refuses to accept a disc is in the drive! Then other times it will work... It won't detect CD-RW discs whatsoever tho.....

Best thing to do is get hold of another drive, borrow one if you can and slot it in place of yours, and try again. If it works you know it is your CD drive. Not knowing what drive you have I can't specify on price, but if you just need a simple CD-RW drive, LITE-ON do good, quick drives that are inexpensive, and even Dual Layer DVD-RW drives can be had brand new for less than £40 these days!