When you have Bluetooth turned on, it does two things; it establishes and maintains a connection with the paired and connected devices that you have, and it scans for other Bluetooth devices. Bluetooth on Windows 10 is constantly scanning for devices. It’s a bit of a battery drain and a bit of a security risk but there’s no off switch for it. If you turn Bluetooth off, it will stop scanning for Bluetooth devices but all your connected devices will also be disconnected, not to mention, Nearby Sharing won’t work anymore.
Out of the box, there’s no switch that you can flip to disable scanning however, you can disable one of the many Bluetooth services that run when the switch is enabled and stop your system from scanning for Bluetooth devices on Windows 10.
Stop scanning for Bluetooth devices
Open the Services panel. You can search for Services in Windows search, or you can open the run box (Win+R keyboard shortcut) and type services.msc in it.
In the Services window, look for a service called Bluetooth Support Services. Right-click it and select Stop from the context menu. This will stop your system from scanning for Bluetooth devices. The interface will still show that it’s scanning for devices but it isn’t.
If you double-click the service, you can read its description which says the service scans for devices when you need to connect a new device. The description does say that it might cause problems with the devices that are already connected and that’s possible though unlikely. If your Bluetooth devices start acting up after stopping the service, you should enable it again.
Once enabled though, your system will start scanning for devices. This fix comes with restrictions and there may be cases where it may not work. Nearby sharing will be impacted because it will not be able to search for other systems on your network.
While it is somewhat of a security risk to constantly allow your PC to scan for Bluetooth devices, a scan doesn’t automatically mean a device can connect to it. In many cases, a Bluetooth device will need some sort of authentication and you will of course have to allow the device to connect to your own system.
There are chances of Bluetooth being exploited but remember that Bluetooth has limited range so the risk is constrained to a great extent. A good precaution to take though is to remove i.e., unpair any devices that you no longer use.