Version of Windows?

What happens if you put a CD in the drive instead of a DVD?

Put a data CD in the drive and then reboot. Immediately press F12 and look for the option to run the diagnostics on the optical drive.

Is the drive still listed in Device Manager? If it is, manually set a system restore point to be safe. Then right-click the drive in Device Manager and uninstall device then reboot. Windows should automatically see and reinstall the drive, and test again.

If Windows doesn't install the device or it still doesn't work, open Device Manager and click Action>Scan for hardware changes

And there's always the possibility the drive failed...

THis is current list from Belarc followed by a previous view.  Note how HL-DT-ST DVDRWBD CH20N [CD-ROM drive] is missing in the first group.

12-1-19

Drives

Yes, all PCs, including desktops have a 3-volt coin cell battery on the motherboard which holds BIOS settings when the PC is off...

Good that you see the drive in BIOS. But I'd clear BIOS and replace the CR2032 battery, if nothing else than to rule that out for ~$2. After you replace the battery and reboot, see if the drive is listed in Device Manager again.

If that drive writes to CD-RW disks you can use one of them for the diagnostics. You don't want to erase it. Just put it in the drive, reboot and press F12 and look for the diagnostics option.

And like I said, there's a chance the drive died...

Did you update to Windows 10 1909 right before this happened?

You might want to clear BIOS and install a fresh battery to see if the system will see the drive again:

1. Reboot and immediately press F2 to open BIOS setup
2. Copy down all current BIOS settings and check if the optical drive listed in BIOS setup.
3. Power off, unplug
4. Press/hold power button for ~15 sec
5. Open case and remove motherboard battery (check Service Manual for details)
6. Press/hold power button for ~30 sec
7. Check data cable connection between optical drive and motherboard and power connection between drive and power supply
8. Reinstall battery (Time for a fresh CR2032 3-volt coin cell battery? ~$2)
9. Close up and connect mouse, monitor and keyboard
10. Reboot
11. See if the drive has reappeared...

You never said if you ran the diagnostics on the optical drive from the F12 menu. You need to put a data CD in the drive first, then reboot and immediately press F12...

I don;pt see it any longer in the Device Manager.  When I ran Belarc Advisor a program than examines everything about the computer, it doesn;t see the CD-ROM either.

I only have a CD-RW.  Can I use it?  Should I erase the data on it to test the F12?

I also did the F2.  Under SATA2>MAIN>  SHowed Device Type Blu-RAy, Device ID HL-DT-ST DVDRW/BDROM  CH20N, DEVICE SIZE N/A.  SO is it seeing it or the battery.  

1.  I had Windows 10, for awhile.  After this happened I did load a couple of updates for something but it made no difference.

2. There's a battery in the tower?

3.  You didn;t say what it mean if the drive is or is not listed in the BIOS setup and how that relates to the battery replacement.  

Windows 10