Tried to partition using Boot Camp and put in windows seven. However it didn't seem to want to make a boot disk and it wanted the partition to be made into NTSF. So I tried to reboot my computer in order to see if I could reformat the partition and my computer will not reboot. I only get the no bootable disk press any key on a black screen and cannot get any further than that. I'm really panicking and wonder if I have ruined my iMac. I do have a backup on a totally different removable disk on time machine. But if I can't even get into my mac I don't know what to do.can anyone please help thank you