When you do this, your computer cannot leave Screen Saver mode without your entering a password (though someone could still reboot your computer and access your files, which is what we meant by this being for those not "overly concerned"). To use a password with your Screen Saver, right-click on the desktop and select Properties. Click the Screen Saver tab and then check the Password Protected box. Click the Change button to select your password, and then click OK twice.