Make sure the CD is working fine: try it on another computer...   can you access your files?   if you can, it's a problem with the PC...  else there's a problem with the CD...    * if the problem is with the PC, it could be your cd drive not properly installed, missing drivers, etc...    * Another simple thing that occurs to me is incompatiblility of media and drive... e.g. you're trying to open a DVD on a CD drive... or a CD-RW with an open session on a simple CD drive...