I have an IMAC. Yesterday I turned it on but it kept loading (there's a white screen with the apple and a circle running all the time). I tried to restart holding the option key but the only icon appear is the Hardrive one and if I click on that it gets the same loading page. I followed the instructions on the apple page and tried to reset NVRAM / PRAM. Result is that I have a brighter white screen page with the apple icon and the circle still running. I went to next step and it suggested to insert the Mac OS X Install disc in the Mac and then hold the "C" key. I did it but nothing came up (apart the apple and the loading circle). Any help on this??? Thank you!!