CD-DVD ROM

if not, the ribbon might not be plugged into the mother board.

If it did work but doesn't now, it is probably dead and needs to be replaced.

have you or anyone else been inside the case recently?

you might get more help with a few changes to your post.
First, it should be posted in the questions forum. Some tech's dont traverse to the Discussions often.

Second, details, details, details. As JD mentioned, did it work before? Is it new? what have you tried so far? Did it give any problems before not being recognized?

Please re-post in the questions forum and add more details, and I am sure someone can help you correct or diagnose the problem.