'System Lock can 'lock' or disable some of windows element like the mouse, desktop ,some control panel's items and much more... So if you want to avoid pepole for changing your screensaver, background and all the 'Appearance' items you can easyly do it whith Sytem Lock. System Lock has a list of all the element that it can disable just check the check box and it's done! You can lock System Lock whith a password so no one can change the 'Locked' items.'