Family Key Logger - this is the best choice, if you want to know what others are doing on your own computer while you are not at home (or office). Install Family Keylogger, set options "Start in hidden mode" and "Hide in task list", so that it makes itself invisible to anyone. After you return, you can just press keystroke to unhide. Family Keylogger - You have the right to Know!

Family Key Logger is the Shareware version. The full version can be purchased by clicking on the "CLICK HERE TO ORDER" button below for around  29USD.