If you need to add Bluetooth to a Windows 10 PC it's harder to find a cheaper or easier solution than this well-reviewed $7 USB dongle from MPOW. There are, however, questions about the safety of trusting included hardware driver CDs or even downloading drivers direct from lesser-known manufacturers. Even the most honest of vendors is not guaranteed to have clean, virus-free driver installation software.
If you purchase a device that is not automatically recognized by Windows then you face the quandary of trusting unknown third-party driver installation software or changing to a different hardware solution.
Such was the case with my own MPOW BH079A USB adapter purchase. The adapter boasts a large number of great reviews and is compatible with many versions of Windows back to XP. Windows 10 did not, however, automatically detect and set up the device and I have a healthy distrust of driver CDs from lesser-known manufacturers. To be fair, no MPOW reviewers cited any cases of malware but I still prefer to avoid software from lesser-known sources when possible.
Fortunately the adapter is basically just MPOW's casing wrapped around the trusty Broadcom BCM20702 Bluetooth single-chip solution which has been around for a decade. Any official Broadcom BCM20702 Windows 10 driver should be all that is needed (e.g., the driver doesn't have to be from MPOW).
Although my MPOW USB dongle is being used on a home-built PC, I went with a Hewlett Packard (HP)-supplied Broadcom BCM20702 Win10 driver (circa 2017):
Install the driver then insert the USB dongle and it should be activated automatically -- no need to turn it on in Windows settings. If you already had the USB adapter plugged in when installing the driver you may need to remove and then reinsert the adapter.
Cheers!