I've been using a dual 2Ghz G5 that was borrowed from my dad's office for a few months. I have to give it back this week, so I decided to reformat, zero out the drive, and re-install OS-X so It would be returned as it was new. Now, I'm running into a problem. I already erased the drive, but the computer won't boot off the OS X install CD. It simply goes to a grey screen with the same "do not disconnect" icon you see on your iPods, meaning it can't boot. Then it gets weird. If you let it sit on this screen, eventually, the fans start to get louder and louder. after a minute or so, the fans run at full blast and the only thing I can do is shut it down. I've also tried installing OS X via firewire target disk mode from another computer, and the same thing happens when it boots. Any ideas why I can't install OS X? thanks!