A notebook computer is valuable, lightweight and portable, which makes it convenient for you to use, but also tempting for potential thieves to steal when it's unattended. You can't always keep an eye on your notebook, but you can secure it in place with a cable lock. One option is the Defcon notebook security combination cable lock made by Targus. It's a good idea to change the combination occasionally for added security.
Turn the numbered wheels on the Defcon lock until your current combination appears in the four windows.
Push the tip of a flathead screwdriver into the reset screw on the side of the lock.
Rotate the reset screw 90 degrees clockwise so that its groove is horizontal to the line running along the side of the lock.
Turn the numbered wheels on the lock to enter a new combination.
Rotate the reset screw 90 degrees counterclockwise to its original position. This saves your new combination. Turn the numbered wheels to a different number.
Turn the numbered wheels to your new combination to test it. Press the locking button to make sure it depresses all the way down, verifying that your new combination works before you lock up your notebook with the cable lock.
Turn the numbered wheels to a different number so people won't see your new combination.
Write down your new combination and keep it in a safe place if you think you might forget it.