I had someone give me a G5 iMac (2006) that wouldn't boot. Being unfamiliar with Macs in general I did my research thoroughly. I still have not found a solution. What I am seeing upon booting up is a white screen with a small grey Apple logo. It will stay here until I shut it off. I did acquire a copy of the 10.4 OS Tiger from a friend yesterday and tried booting up the disk (by pressing "c"), but all I get is the same white screen with an Apple logo in the middle. I have exhausted many resources, but am not sure I am even looking in the right direction. Any help would be appreciated.