If Bluetooth driver is missing or gets removed after a Windows Update, add the legacy driver from the Device Manager, install the correct driver from your manufacturer, etc.
When your Bluetooth mouse suddenly stops working and the entire Bluetooth functionality disappears from your PC, no toggle switch, no Bluetooth in Device Manager, it usually indicates a deeper issue ...
If the Event ID 16, Bluetooth fails to connect keeps troubling you; this post may help. Event ID 16 appears in the Windows Event Viewer if your computer has failed to establish a Bluetooth connection.
Results that may be inaccessible to you are currently showing.
Hide inaccessible results