Not reading the info on my DVDR

[emmcee]

I burned a backup CD in January, and today I had it in my laptop looking for photos on it and then took it out to check another cd, later putting the first cd back in and suddenly instead of showing me everything on it, it was saying "drag files to this folder to add them to the disc". And it is also telling me that I have 793 MP free of 4.37 GB so it appears the info is still there, but I just can't access it. Could anyone tell me what I might be able to do, if anything, to retrieve my information once more?

Not sure if you need this info, but I am using Windows Vista Home Premium

Thank you for any help you can offer...I am stumped.

E