In case someone else has this issue, this fixed it for me twice - both happened a few weeks apart.   Shut down the PC Unplug and fully discharge the PC by holding the power button for 20 seconds Plug back in and power on Log into Windows and open device manager Uninstall AS Media 3.1 eXtensible Host Controller Uninstall problem USB device (this is actually the bluetooth device) Right click and device and click scan for changes Bluetooth should show up again in device manager and in settings.   I've tried this without fully discharging the PC and it didn't work - PC must be discharged so BIOS can enumerate the PnP devices again.
It's April 2020 and I have run into a similar problem on my Alienware R8. I lost all Bluetooth functionality. The on-off switch in Windows 10, the icon from the system tray, and so on. It was a hardware issue, stemming from the fact that I had opened up the case of the Aurora R8 to looky loo and blow out the dust. It was after that when I lost contact with anything to do with BT. I think I somehow put the left side cover on slightly askew. Yes, I did close it up, but that is when my difficulty with all things BT began. Today I removed the lid, swung out the power supply, and CAREfully put everything back together. My BT headphones immediately worked as usual. This was after 45 minutes with a Dell hardware tech and 30 minutes with a Microsoft Windows guy. Hope this saves someone a major hassle.
Aurora R8, bluetooth not working, SOLVED