Bluetooth 50 Usb Adapter Cm390 Driver Install | Ugreen

If Windows Update fails, you need the generic Realtek driver. UGREEN does not host drivers on their main site (ironically), but the chipset manufacturer does.

Step 1: Download the official Realtek Bluetooth 5.0 driver.

Step 2: Extract the ZIP file. Step 3: Open Device Manager (Right-click Start button → Device Manager). Step 4: Look for an unknown device under "Universal Serial Bus devices" or "Other devices". It might say "Unknown Device" or "Bluetooth Adapter". Step 5: Right-click the device → Update driver → Browse my computer for drivers → Let me pick from a list... → Have Disk. Step 6: Browse to the extracted folder and select the .inf file (usually rtbt.inf or rtl8761b.inf). Step 7: Click OK → Next. Ignore the "This driver is not digitally signed" warning if it appears (for Windows 7/8). ugreen bluetooth 50 usb adapter cm390 driver install

Step 8: Reboot your PC.

| Problem | Solution | |---------|----------| | Device not detected | Try a different USB port (preferably USB 2.0 if USB 3.0 fails). | | Driver installs but Bluetooth doesn’t work | Uninstall any existing Bluetooth drivers (like from Intel or Broadcom) first. | | “Driver is unsigned” error (Windows 7/8) | Restart and disable driver signature enforcement (press F8 during boot). | | Can’t find the device in Device Manager | Check if the LED on the dongle lights up. If not, test on another PC. | | Bluetooth mouse/keyboard lag | Install the latest driver from Realtek (v1.9+ recommended). | If Windows Update fails, you need the generic Realtek driver

Sometimes the driver installs, but Windows uses a generic Microsoft driver that lacks Bluetooth 5.0 features. Here is how to force the correct driver.

Step 1: Open Device Manager. Step 2: Expand "Bluetooth" . Step 3: Right-click "Generic Bluetooth Radio" → Properties → Driver tab. Step 4: Click "Update Driver" → "Browse my computer..." → "Let me pick from a list..." . Step 5: Uncheck "Show compatible hardware". Step 6: In the left pane, select "Realtek Semiconductor Corp." . Step 7: In the right pane, select "Realtek Bluetooth 5.0 Adapter" or "Realtek Radio" . Step 8: Click Next. If you see a compatibility warning, click Yes. Step 2: Extract the ZIP file

Result: Your device now uses the manufacturer driver instead of Microsoft's generic stack.

The CM390 typically uses a Realtek or MediaTek chipset. On Windows 10/11, drivers usually install automatically. If not, follow these steps: