Ive had my late 2009 iMac Password Protected for years, but since upgrading to the newest OS, it doesn't ask for my PW anymore. I Googled this, and the instructions were: System Preferences Security & Privacy Tab General Tab Require PW after sleep or ScreenSaver Show all But now, when I click on the Apple Logo, and then System Preferences....I see NOTHING about Security & Privacy or any of the other subsequent tabs. Something changed. Can someone please tell me how to PW protect my iMac? Thanks in advance.