Hi, I have a iMac(20") for about a year now and its ran great up untill now. It is hanging on boot. Sometimes its the white screen with apple logo and spinning gear, other times the screen goes blue and i can see it load a mouse cursor for about 2 seconds, then the screen goes through a few shades of blue and the spinning gear re-apears with no apple logo. The computer then loops. I tried to boot to safe mode, but as i have the sound off i am not sure i am holding the shift key at teh proper moment. If anyone has any advice, please, please let me know. p.s my mac reinstall cd is about 8hrs drive from where i am, and i do not know if mac issues replacement cd's.