Have you tested both cds and dvds in the drive? Will none of them play? If you go into My Computer and right click on the drive icon, then hit explore, can you see the contents of the disk?
The next test is to use a bootable disk in the drive and restart the computer. You need the boot order set in the bios to look for a bootable disk in the optical drive first, rather than one of the hard drives, so that it will boot into this disk instead of the operating system. The purpose of this test is to see if the drive is working at all, outside of any problems in the operating system.
A bootable disk would be something like a Windows install disk, or restore disk. You can also find them online. The ultimate boot disk is free to use, but you'll need some way of burning it to a disk. You can get the ISO here: http://www.ultimatebootcd.com/download.html