If your computer has a disk drive, you can use the provided mini-CD to run setup.exe . Installation Steps: Plug the adapter into a USB port.
Install Driver Booster or Snappy Driver Installer (free versions). They will auto-detect and install the correct CM390 driver in one click. ugreen bluetooth 5.0 usb adapter cm390 driver
Update the driver. Older generic drivers have high latency. The official Realtek driver reduces HID polling latency. Also, ensure line-of-sight—the CM390 is small, so plugging it into the back of a metal desktop tower kills the signal. Use a front port or an extension cable. If your computer has a disk drive, you