I've been looking around, and there doesn't seem to be an answer to this but, oh well...

Because of failing RAM, my father recently formated and reinstalled everything that was windows related (his computer has dualboot with MDK 10.1). At the moment he didn't realize the reason for the various problems he had. Before doing so, he loaded linux and saved his data on a couple of cds - of course, he didn't quite catch there were problems there too. When K3B told him everything was fine, he didn't check it up.

So now, here I am, with 2 failed cds that have data on it. Would anybody know of a way I could at least try to recover it ?

First thing to try is knoppix. Failing that there is sleuthkit+autopsy www.sleuthkit.org .