In trouble with GF over lost memories

So. I lost my hard-drive contents, but did back-up all the really important files, including my gf's photo collection (some of the pics are over 30 years old and whilst they can be re-scanned, this was a very very time consuming process).
I backed-up the discs to a Lite-on CR-RW and it was burnt in a Lite-on CD-burner. When I came to move all my documents back, about 80% of the photos wont copy. Even when i try to open the containing folder on the CD 'My Picutres' the PC gets very slow, but eventually the folder opens. When i try and copy the photos that didnt get copies when I did a bulk-copy, it simply says that it 'Cannot Read From The Source Disc' :-(
Has anyone had this before?? are the photos all lost, due to a cr** disc?

as always, any feedback appreciated :-)

First port of call is to check the disk in an alternative drive. Test it on a friends CD drive and see if you have the same trouble. It could be that you either have a duff CD drive or that as you suspect, a duff piece of media.

Another check is to open a photo editing program and see if you can open random files from the CD in it.

Yes. Makes good sense. I have some pc's in work. I have tried opening them with paint shop pro, but the system just jams up.

cheers again :-)