At anytime, happened to go leaving your PC, left click on the maze lock icon viewed in the system tray which will lock PC with your preset pattern. Again to access the desktop, draw the secret pattern with your mouse.
Others trying to unlock your computer happens to draw three times, and if they draw wrong patterns, it sounds alarming siren and like screensaver it will be locked automatically blocking the access for 1-3 minutes or even shutdown computer. Also you can set Autolock computer when left alone for some time. And if not necessary, right click on the maze lock icon in your system tray and click ‘Disable AutoLock’. Go to General ► Options dialog to configure these type of settings.