We need some more info from you here.
When did it start happening? Suddenly?
Is this a newly installed CD drive? You say when you install "software" disks, nothing happens. Do music CDs work?
When you insert A CD, can you see the light on the front of the drive flashing at all?
What version of windows are you running? If XP, go into your device manager and tell us what it is saying for your CD drives there. Does it say it is functioning normally, or is there a yellow/red warning symbol?
Sorry for all the questions. There could be a number of causes for what you describe, and as we can not physically take a look at your computer, we need you to be the eyes.