First don't uninstall the Bluetooth (BT) driver or and anything else.
If you do, you might struggle (even more). There might be better ways.
(I suspect it has nothing to do with the driver, but the switch that connects/disconnects the hardware. Then the computer can't recognize it. It might be just some static electricity that disables it).
in brief: I tried many things (BT comes and go once or two per week), the only way I found that always works (which is also the quickest, but maybe not the safest) is to physically remove (plug out) the Bluetooth hardware (the WLAN card). Then boot the computer. When windows are loaded, shut it down, put back the WLAN card, and reboot again. The Bluetooth will then be reconnected/recognized. It takes 5-8 min.
I tried many times to uninstall/reinstalling the BT driver, rebooting (removing the plug and battery after it) sometimes it works (but I suspect for other mysterious reasons), but it failed most of the time.
Don't forget to Describe your bug in the feedback hub (it's an MS app).
I'm not sure these step will change anything (try it if you believe it's a driver issue)
- in troubleshoot settings/diagnostic data enable "full". In troubleshoot/recommended troubleshooting, set it to "fix the problem for me without asking" (I guess you have more chance to get help).
- it's possible to contact a windows technician: just type "help" in windows menu. You will first talk with a (dump) robot, then with a technician.
- then ask the Microsoft technician your Bluetooth driver. He will ask you your name (you can give mine) your windows version and your bios version (run
dxdiag to find out, to copy past, you need first to "save all information").
- before trying to install the driver after you uninstall one that did not work, you might need (or not) to run the Device Cleanup Tool (thanks to Uwe Sieber!). Run it as admin, it will give you the list of phantom devices, delete the one related to a connection (I deleted every one, but read this before doing it). Notice that if the BT show under "hidden devices", it'll then be removed. (Not sure this is useful though).
- install the driver given by the Microsoft technician. (Which in my case come from dell, and did not work).
- then go in device manager, look in view/"show hidden device", and update it
- unplug your computer for 10 secs, then plug it back.
- if the driver only shows in the hidden device (eg. in the section "other devices"), but don't work, wait on this step and bite the bullet. Unless you have magical power, don't try anything else. Just connect the computer to the internet, just wait for Microsoft to solve it automatically (it might take a few days ― praying and offering sacrifice to Gods might help). In my case trying to fix it after this step was just a waste of time.
And then, if you are a brave man/woman, run this (black) magic PowerShell command
Disable-NetAdapter * so you will have to start the whole process again (it might break again your Bluetooth). But... you will definitely gain more wisdom like Sisyphus. (But before trying read this)
ps: the problem occurred on a Dell Inspiron 3520, BIOS Ver: 04.06.05. The MS technician asks me to download this driver from Dell (with it, the driver only shows in hidden device, as mentioned above), but he told me that all drivers provided by Dell for my computer would work (even if they don't specify Windows 10 "because the computer, runs then in Compatibility mode and some of the updates on the drivers where done back on 2018".)
Reading this comment gave me 2 ideas that might help: it said: "you need the vendor-specific software for Windows to turn Bluetooth ON again" (it's not a driver but the switch provided by the "vendor-specific software for Windows" ― something equivalent to the Software Wireless Switch discussed here. On Linux, there’s
- I tried connecting the Bluetooth running some random Linux/Ubuntu ubuntu command (is more an alchemist experiment than anything else). (No need to install it, Ubuntu can be run from a USB). Actually many people have the same problem with Ubuntu. Look at this thread: How to unblock something listed in rfkill?
"Hard blocked" cannot be changed by software, look for a wifi toggle on your keyboard or edges of the laptop; the device can also be hard blocked if disabled in the bios. "Soft blocked" means "blocked by software". A faulty driver or other kernel modules can lead to connectivity loss. (Is there a PowerShell equivalent of
rfkill unblock Bluetooth?).
... I also tried to restored windows using a system image that was working with Bluetooth. But it did not work. So it doesn't seem to be a driver issue, nor stored in the registry. Can it be solved by editing the bios file? Or is it simply static electricity that disables the device (which would explain the plug trick).
If that doesn't work, just buy an external USB BT hardware.