Active Key Logger is, without doubt, the best choice if you want to control what others do on your PC when you are absent.
You can adjust the `Start in hide mode“ parameter so that Active Key Logger starts running invisibly, even to the system tray. This way Active Key Logger records in logs all the activity produced on your PC while you are not there. This includes the keys pressed, and also the screenshots taken periodically.
It is an ideal tool to control what your children do on the PC, and watch for suspicious behaviour.
NOTE: Remember that Active Key Logger, as it's a tool that works hidden and collects information on all things done on the PC, could be detected by your antivirus as an intruder.