[Lattimer]

My iMac will boot, but at some point, either while booting or after I login, it displays the message in the attached pic. Is my HD corrupted? I tried to reinstall OSX, but it says there was an error and couldn't complete the install.....thoughts?

[besson3c]

I would first test your RAM before testing your hard drive. Do you know to run hardware tests?

Yes, that is bad if it reoccurs at regular intervals. That is called a kernel panic.

[Big Mac]

It's also bad from the standpoint that it's an anachronistic dump-to-the-screen style KP, which is virtually unknown today. In the rare event of a KP in modern versions of OS X, you get the attractive, translucent grey box on your screen saying that you must restart your computer, printed in multiple languages. The appearance of the text dump hints that it's an even more serious issue because the system can't even give you the relatively graceful KP.

What version of OS X are you running? If you're on a really old version like 10.1, what I wrote in the previous paragraph doesn't apply.

[Lattimer]

I believe I'm running 10.3...I've seen the translucent grey box a few times as well...I've even been able to get to the desktop and work for awhile before it goes nuts. If it goes to sleep, after awhile the fan kicks on high and stays that way until I pull the plug.

I've had the power supply replaced twice and the logic board replaced once on this thing. Never had a Mac give me so much trouble.

ARGH

[besson3c]

If it is a bad stick of RAM (and that is fairly likely), it will be some relief to you that the fix is not terribly costly...