It's possible the CD-ROM and/or the CD's just needs a clean. The smallest of scratches on a CD in the wrong place can stop it from being read. The laser head in a CD-ROM is a little bigger than the width of a hair, so if a hair has found it's way into the drive this can also cause the drive to not read the CD's.
Maybe if it is a CD that plays automatically when u insert it, the application that runs is crashing, so maybe you should try disabling autoplay. i cant remeber exactly how to do that, look in control panels!