Apple iMac (Early 2008) - Manual (Page 41)

Chapter 4 Problem, Meet Solution 41
Problems That Prevent You from Using Your iMac
If your iMac won’t respond or the pointer won’t move
 Make sure the mouse and keyboard are connected. Unplug and then plug in the
connectors and make sure they are secure. If you have a wireless keyboard or mouse,
make sure the batteries are fresh.
 Try to force problem applications to quit. Hold down the Option and Command (x)
keys and press the Esc key. If a dialog appears, select the application and click Force
Quit. Then save your work in any open applications and restart your iMac to be sure
the problem is entirely cleared up.
 If you are unable to force the application to quit, press and hold the power (®)
button on the back of your iMac for 5 or 6 seconds to shut down the computer.
Unplug the power cord from the iMac. Then plug the power cord back in and press
the power (®) button on your iMac to turn it on.
If the problem occurs frequently when you use a particular application, check with the
application’s manufacturer to see if the application is compatible with your iMac.
To get support and contact information for the software that came with your iMac,
go to www.apple.com/guide.
If the problem occurs frequently, you may need to reinstall your system software.
See “Reinstalling the Software That Came with Your iMac” on page 48.