can anyone please help i have an intel mac mini. and it froze up this morning and i had to hard reboot it. now it is stuck on the grey apple screen and will not even boot to the install cd. i have rebooted holding down the option/alt key and i can choose the disk and or the hd but neither will boot it just sits on the grey screen. i have pulled the memory and swapped it with no success i have swapped the HD with no success still cant boot to HD or CD please help.