I know this has been asked and answered a million times. But it still doesn't work for me. So, I hope someone helps me. System preferences -> Security Disable automatic login is checked. Require password to wake this computer from sleep or screen saver is checked. System preferences -> Desktop and screen saver. Screen saver is set to "Computer name". Testing this works. Screen saver is set to fire in 3 minutes. Try-1: System preferences -> Expose and spaces -> Expose Bottom right corner set to "Start screen saver". I close this window and move my mouse pointer to the bottom right corner. Nothing happens. Change the bottom right corner to "Sleep display" and move the mouse pointer there. Works. Change the bottom right corner to "Dashboard". Works. Change it back to "Start screen saver". Doesn't work. Try-2: Keychain access preferences Show status in menu-bar is checked. I see the lock icon on the menu bar. Click on it and choose "Lock screen". Nothing happens. I've tried this a million times and it never works. What am I missing? I'm using Macbook Air on 10.5.2. It asks the password when I put the notebook to sleep and wake it back up. Otherwise, the display sleeps, but as soon as I touch something, I am back to my usual desktop. Am I asking too much from my first mac when all I want it to do is to lock the screen? Please help.