Why is my Laptop DVD drive not working or even showing up in my computer?

I have a Toshiba Satellite Laptop with Windows 7 and all of a sudden I can not see or access my DVD drive. It will spin up bu never read the disc. I had a friend that had the same problem and he updated to Windows 7 and all is well. I upgraded mine and it has the same problem can someone lead me in the right direction?