CD drive won't recognize disk

Hello everyone. I am having problems with getting my computer to play a game. I am taking a Agriculture college course and one of our projects is to play one of John Deere games to build a farm. Now I bought this same game last year, installed and played it everyday for several weeks. Then when I found out about this project, I went to play it again and it done nothing. I re-installed it and it asks me to insert the disk, but it's already inserted. I go to My computer and click on the CD drive, but there is nothing there. I thought it might have been the game, so I bought 2 more John Deere games and got the same result. But if I put in any type of DVD, such as a movie it does the whole auto run and plays the movie. I've tried everything I can think of and suggestions from co-workers, and I'm close to taking to Geeks on Call and eating the expensive bill for it. Anyone got any suggestions?