Posting this here in case it helps anyone with an ongoing issue I've had for 3 or 4 years now.

After building my new rig a few years ago all went very well. Until my Pioneer BD-R drive decided to vanish for no good reason. Drive was a good drive, tested in other rigs, Bios saw it, Windows 10 did not.

Maybe I'm old school but I still like to back up stuff, and record-able Blurays seemed ideal a few years ago. The drive worked flawlessly on my previous rig. It initailly was recognised on my new W10 rig, but I never had need to use it until I tried months later. Lo-and-behold W10 decided not to recognise it. Tried all the tricks I found online to get it working, but the only thing I found 'worked' was to leave a BluRay movie disc (Pacific Rim as it happens) in the drive. Cool.

Not really. As soon as I swapped the disc out for a DVD/r or any other disc, the drive would vanish from windows. Only restarting the computer with said Pacific rim movie would bring it back, but only temporarily.

Hopefully found the cure tonight, windows reboots with empty drive and still recognises the drive, discs are loaded, I'm happy so far. Even managed to burn a Blu ray.

The issue turned out to be in the bios. Seems many board manufacturers have a setting that over-rides your windows power settings (which was something i found in my searches to check) that not only renders optical drives invisible due to low usage, but can also have very detrimental, life shortening, effects on your HDD's. It's called 'ALPM', or Aggressive link power management. If enabled it basically overrides your power setting in windows that your drives save so much energy they may not even be recognised in windows. I've read many reports that it also causes HDD's to run down and then up so often to the point where it ****'s them up. That may be conjecture, but go look it all up.

All I can say that disabling ALPM in bios has suddenly made my BD-R be useable again, deep joy.