Dave H. is right. We have an HP Spectre 13, and it was showing all the symptoms. Conventional driver updates didn't work - said had the latest driver. Lie! (Yes, it also said something about manufacturer might have newer updates - didn't we pay you to know that MS??)
- Make sure you know what chipset your Intel wireless is using - https://downloadcenter.intel.com/download/27622/Wireless-Intel-Wireless-Bluetooth-for-Windows-10?v=t
- Download the correct driver set (32 bit vs. 64 bit)
- Verify that your PC has the v20.20.x Intel Bluetooth driver (using device manager; uninstall the fussy USB driver section, then shut down and restart if necessary in order to get the Bluetooth section of device manager to reappear - see previous comments if you don't know how to do this)
- Start the Intel driver package you downloaded in administrator mode (if you are not an admin. for your PC, you will need to find someone who is); right click on the download to get the menu item you need - if it isn't there, you are not an admin. You do not need to uninstall the current Intel bluetooth driver first - the package does that for you.
- I took the "typical install" route; your needs may be different (and if you don't know, use typical)
- When the install finishes, you should see the bluetooth button in the "Bluetooth and other devices" section of Settings; you should now be able to turn it off and on without it disappearing. Enjoy!
I did this in Win 10 Home v.1709, but the process should be the same with Pro.
Updated thru KB4103727.