The recent update to Windows 10 includes a new feature called Dynamic Lock, which allows your PC to lock automatically when left unattended. You start by wirelessly connecting a device to your PC over Bluetooth.
Once you’ve enabled the Dynamic Lock feature, your PC automatically locks itself 30 seconds after that Bluetooth link is broken. Say, when you pick up your phone or headphones and walk off.
Start by pairing a device with your PC. We recommend using your phone. Open Settings, then Devices, and finally Bluetooth. On the phone’s Bluetooth screen, make sure it is discoverable, then connect from the PC.
Once they’re paired and connected, go back to Settings on your PC and choose Sign-in options. Scroll to Dynamic Lock at the bottom of the page and tick the box labelled Allow Windows to detect when you’re away.
Remember, this only protects you if you carry the phone with you away from your desk to break the Bluetooth connection. Some clever devices can maintain the connection over 100 m. But, when you return to your PC and your phone reconnects, the PC will automatically unlock.