I'm somewhat computer illiterate & I have a problem with my Mac; it recently began freezing up with a grayish screen containing a centered message box which reads something like: "You must shut down your computer. Hold down the power button until it shuts down. Then press power button to restart." Upon restarting, within a few short minutes it freezes again with the same message. This is now constant. What is wrong, & what can I do to rectify the problem? ANY help would be greatly appreciated. You can reach me here or at my AOL address: EOLORDJESUS@aol.com Thank you

Insert the OS X installation disc and boot with the "C" key held down. Does it boot to the installer?

Looks like it went kernel kaput.

http://macosg.com/kp/1/

http://macosg.com/kp/2/