Bt Watcher is dedicated mainly for professionals who travel a lot with their notebook. It detects by bluetooth when you leave the room and automatically locks your computer. The program knows if you are near the computer because it looks for your bluetooth-enabled device, typically mobile phone. Immediately after installation you can assign your mobile with it, and you can forget about locking screen: It will do it every time you will leave the computer's vicinity. To unlock the screen you must enter your Windows password. You can protect it by password to get more security, password are stored in encrypted form. It can also shutdown your computer, or start other task defined by you.