Apple MacBook (13-inch, Aluminum, Late 2008) - Manual (Page 53)

Chapter 4 Problem, Meet Solution 53
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, save your work in any open applications and restart the computer to make sure
the problem is entirely cleared up.
If the problem occurs frequently, choose Help > Mac Help 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 it is compatible with your computer. To get support
and contact information for the software that came with your MacBook, go to
www.apple.com/guide.
If you know an application is compatible, you might need to reinstall your computer’s
system software. See “Reinstalling the Software That Came with Your MacBook” on
page 61.
If your MacBook freezes during startup, or you see a flashing question mark, or the
screen is dark and the sleep indicator light is glowing steadily (not in sleep)
The flashing question mark usually means that the computer can’t find the system
software on the hard disk or any disks attached to the computer.