How can I disable the trackpad when my mouse is plugged in on Lion?

Solution 1:

Thankfully, you can still disable the trackpad in OS X Lion.

Open System Preferences, click on Universal Access, select Mouse & Trackpad and click on Trackpad Options... at the bottom. Tick the checkbox "Ignore built-in trackpad when mouse or wireless trackpad is present".

Solution 2:

When you open up System Preferences, do not open up Trackpad or Mouse preferences as seen in the attached photo.

Look down in the lower right hand corner for the Universal Access preference and open that up to get to more features for both the trackpad and the mouse, including the 'permanent' solution to stuck/failed built-in trackpad or mouse issues ... see the 2nd picture of the Universal Access preferences, which include 'Ignore Built In Trackpad if Mouse is used...' option.

Now, you can practice not using your cheap or deprecated trackpad on your Mac Book ... and if you hit the trackpad or busted mouse click key on the trackpad by accident, it no longer will stop you or your mouse from working as if the trackpad no longer exists ... cheaper than fixing the cheap bastard !

No, but there is an option labeled "Ignore accidental trackpad input" in System Preferences: Trackpad. Does that help?