Just as it says I cannot boot from the Macintosh HD I have windows vista installed and I can boot up in wodows but it will not boot from the mac HD nor will it boot from the Leopard CD I have tried a safe mode boot, and I don't know what eles to try I have even tried to wipe the drive clean but it just hangs on the white screen with the wheel??? The only thing it will do is if I turn it on and hold down the option button and select boot from windows it will do with no issues!! Even if I try to boot from boot camp in windows to restart using MAC it just hangs there and i get the "blue screen" and nothing happens. Please some one help me I am new to MAcs and this is my first mac!!!!