Q: Bluetooth totally gone in windows 10

In Windows  Control Panel -> Device Manager, click on View and enable Show Hidden Devices. Do you see your BT adapter? If yes, is Windows configured for Automatic Updates?

Try a SMC and NVRAM Reset

Reset the System Management Controller (SMC) on your Mac - Apple Support

How to Reset NVRAM on your Mac - Apple Support

You may also need to repair/re-install BC6 drivers which can be downloaded using BC Assistant to a USB flash drive.

Can you check the versions of drivers? If you have older drivers in the driver store, you will need to remove them using pnputil.exe.

Now when the drivers are gone, go into Device Manager, click the Action drop down menu and select Scan for hardware changes and if all goes well, install new Bluetooth drivers. After that, check if they are up to date as well by right clicking on them and Update Driver Software.

Good luck.

It might help to check in your OS X for bluetooth hardware info so you can find appropriate Win 10 drivers more easily.

Hold Option (Alt) key and click on Apple logo and go to System Information -> Bluetooth.

Post information here so we can provide URLs.

The BT Device(s) have been removed. They should come back. After an SMC and NVRAM Reset, please run setup.exe from the Bootcamp folder and check. It is possible to install individual drivers by hand with Scan for Hardware Changes. If you use WHQL BT drivers, it will not work.

Are there any entries in hidden devices? Also, does msinfo32 show any BT entries?