When an audio CD is placed in the CD-Rom drive, it starts playing. When a program CD-Rom is placed in the drive, we receive the message that the drive "is not accessible. Incorrect function."

We are also getting the same message with our external drive - it shows up as F, G, and H in My Computer but none are accessible, and they just have plain icons that say "removable." 

But the external drive shows up just fine in a different computer, and shows up as just one drive letter and with a blue icon for the WD Media Center.

We are having other problems with the computer (network adapters and their drivers), but we need the CD-Rom drive working first before we tackle those, so that we can repair those issues w/ the program CD's.

We will greatly appreciate some direction with this - Thanks for your help!