I worked on a computer for two days doing everything I could find on the web and everythihng I could think of to recover the lost optical (CD/DVD-rewritable) drive on a Windows XP computer.
I tried the recommended REGEDIT changes deleting the Upper and Lower Filters and Microsoft Mr. Fixit but they didn't fix the problem. I put in a new optical drive with the same problem. I checked all hardware. Defragged. Did a complete CheckDisk. Nothing would fix the problem.
Every time I would install ANY optical drive, I got the nasty yellow ! on it with an Windows error Code 39 message saying the driver wouldn't load.
I finally fixed it!
It was a Virus.
The Virus had infected 6 files and was keeping Windows XP from properly loading the optical drive drivers.
AVG didn't keep the Virus off the PC or fix the problem when I did a complete scan. This was a big surprise to me.
Avast removed the Virus when I did a "Boot Scan". Avast detected and deleted 6 infected files that AVG didn't find.
After the Avast "Boot Scan", the optical drive still had the yellow ! on it and the Windows error Code 39 but after I Uninstalled the optical drive and scanned for hardware changes, it installed the driver with no problem!
Avast is a free antivirus program that can be downloaded from http://www.cnet.com Just search for Avast, download it, register for the Free version, Open the User Interface, click on the Scan Computer link, click on the "Boot-time scan" link, click on the "Schedule Now" link. Restart your computer and wait for it to scan every file. It should find several infected files.