I've had some CDs which have become either wholly or partially unreadable on the PC which I created them on. I found that I could read them on another PC, and I later found that I could read them with the the original PC after I'd changed the CD drive.
So you might want to see if you can access the files on a friend's PC and then copy them to a fresh CD which (hopefully) your PC will be able to read.
Otherwise you might need to try some file recovery software. This might do the job:
http://www.download.com/CD-Recovery-Toolbox-Fr ee/3000-2242_4-10646814.html
but the ultimate file recovery program (for CDs and DVDs) is Isobuster. It's a commercial program, which costs $29.95 for the key to unlock its full potential. However you can download it and select 'Free functionality' to carry out many tasks. It might well do what you require without payment:
http://www.isobuster.com/isobusterdownload.php
Chris