Download "Bluetooth Version Detector" (free tool). Run it. It will show the active version.
If the driver is installed but audio playback on Bluetooth headphones is choppy: ugreen bluetooth 50 usb adapter cm390 driver install
It is rare, but you may have a defective unit. UGreen has a solid 18-month warranty. Return it, but there is a 99% chance that following the manual registry fixes above will resurrect your dongle. Download "Bluetooth Version Detector" (free tool)
You can install the driver using the physical media included with the product or by downloading it from the official site. Question about Ugreen CM390 - Galaxus If the driver is installed but audio playback
With the correct driver installed, the CM390 demonstrates the capabilities inherent to the Bluetooth 5.0 standard:
Users love this dongle because it plugs flush into a laptop or desktop, but the installation process can be finicky.