You will find the Atheros AR5BBU12 in:
You can download the 64-bit Windows 10 driver directly from the Lenovo Support Site . Bluetooth Module Atheros Ar5bbu12 Driver
Sometimes Windows Update will push “Qualcomm Atheros Bluetooth 4.0+HS” – this is not correct for the AR5BBU12 (which is BT 2.1/3.0). Avoid this, as it often creates a ghost device that doesn’t function. You will find the Atheros AR5BBU12 in: You
The is a classic case of abandonware. With patience, community modded drivers, and disabled signature enforcement, you can usually get it working on Windows 10. However, Windows 11 is increasingly hostile to this legacy hardware. community modded drivers
Best for: Stability and full feature support.