To lock your Mac with a click

1.
Open Keychain Access (first open the Applications folder, then open the Utilities folder; Keychain Access is in the Utilities folder).
2.
From the Keychain Access menu across the top of the screen, choose “Preferences….”
3.
Check the box to “Show Status in Menu Bar.”
4.
Quit Keychain Access.
5.
You'll now see a tiny padlock icon on the right side of your menu bar across the top of your screen. Click that padlock icon to get the menu shown below.

6.
Choose “Lock Screen.” The screen saver will start and no one can access your Mac unless they know your login password.

Get Mac OS X 10.4 Tiger: Peachpit Learning Series now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.