| Symptom | Likely Cause | Solution | | :--- | :--- | :--- | | Dongle detected but no Bluetooth radio in Device Manager | Windows 7 loaded the default USB composite driver | Manually force update driver via "Have Disk" | | Pairing fails with "Driver Error" | Conflicting Bluetooth stack (e.g., Intel or Microsoft) | Uninstall all Bluetooth software from Programs and Features, then reinstall dongle driver | | Device pairs but disconnects after 10 seconds | Power management is suspending the USB port | Device Manager → Universal Serial Bus controllers → Right-click each Root Hub → Properties → Power Management → Uncheck "Allow computer to turn off this device" | | Bluetooth 5.0 speed is slow (same as 4.0) | Windows 7 lacks the 2M PHY support | This cannot be fixed. Windows 7 does not support Bluetooth 5.0's physical layer enhancements. You will only get stability, not speed. | | Code 43 (USB device malfunction) | Faulty driver signature or corrupted INF | Boot into Safe Mode, delete the dongle from Device Manager using "devmgmt.msc", then reinstall using Method 1 |

Download the driver package. Search for "Realtek Bluetooth 5.0 driver Windows 7" directly from the Realtek website or a vendor like UGREEN (they provide legacy drivers).

This is a critical, often overlooked step. Because Windows 7 is older, it was originally designed to recognize "SHA-1" signed drivers. Modern drivers (like those for Bluetooth 5.0) are signed using "SHA-2" encryption for security. If your Windows 7 is not fully updated, it will block the driver installation because it doesn't trust the modern signature.