One of the most basic things we can do to protect our data when we are using computers is to make sure no one else can use your computer after you have logged on. To this end, get into the habit of locking your screen whenever you leave a computer. The process is simple:
Ctrl-alt-del (hold the control`1 and alt keys, then strike delete). Your screen will go black with four options. Click “Lock” and the next person to click any key or move the mouse will be asked for your password.
Apple menu- Lock screen
Of course, these steps require the user to remember to do them, and there are plenty of situations in which one might be distracted when they are called away from their computer. To minimize the time that your computer is unlocked if you forget to lock it when you leave, you should set the screen to automatically lock after 60 seconds.
Start – Settings – Accounts – Sign-in Options
In the “Additional settings” change the “If you have been away, when should Windows require you to sign in again?” to “1 minute.”
Apple menu – System Settings – Lock Screen
In the “Require password after screen saver begins or display is turned off” menu, choose “After 1 minute.”