I have an older eMachines desktop (running XP) that came with a DVD-CDR drive, then I installed a DVDR soon after. A year or so ago, the CD drive quit--it still shows up in My Computer, and troubleshooting doesn't show any errors, but the computer won't read from or write to it. Since I had the 2nd drive, I didn't worry about it. Now, the 2nd drive has quit--same symptoms. I tried updating drivers, but that didn't work, so I bought an inexpensive Samsung external USB-DVDR drive. Same thing. The drive works fine on my newer desktop (Windows 7), but the older desktop "sees" it, says it's working correctly, shows it as updated and installed, but won't read from or write to it. If I try to just double-click or drag something to the new "Drive K," I get an error message that the CD drive is "inaccessible." I'm at a loss. Of course, I can't install anything from the drive's CD, because I can't get any CDs to read! However, when I plugged in the USB, it installed fine on both desktops, at least according to the troubleshooter.
New Samsung is: Samsung 8x Slim DVD+/-RW Slim USB External Drive, Black SE-208DB/TSBS (said it's good for XP, 7, and 8)
I'm at work now so I don't have any more particulars on the desktop, I'm sorry.