Apple MacBook Air (11-inch, Mid 2011) - Manual (Page 39)

39 Chapter 3 Problem, Meet Solution
Problems That Prevent You from Using Your MacBook Air
If your MacBook Air doesn’t respond or the pointer doesn’t move
On rare occasion, an application might “freeze” on the screen. Mac OS X provides a way
to quit a frozen application without restarting the computer.
To force an application to quit:
1 Press Command (x)-Option-Esc or choose Apple () > Force Quit from the menu bar.
The Force Quit Applications dialog appears with the application selected.
2 Click Force Quit.
The application quits, leaving all other applications open.
If you need to, you can also restart the Finder from this dialog.
Next, restart your MacBook Air to make sure the problem is entirely cleared up.
If the problem occurs frequently, choose Help > Help Center from the menu bar at the
top of the screen. Search for the word “freeze” to get help for times when the computer
freezes or doesn’t respond.
If the problem occurs only when you use a particular application, check with the
application’s manufacturer to see if the application is compatible with your
MacBook Air. To get information for the software that came with your MacBook Air,
go to www.apple.com/downloads.
If you know an application is compatible, you might need to reinstall the application.