Back up the disk and use Disk Utility to format it as a single Mac OS Extended (Journaled) volume. Restore your information to the disk and try using Boot Camp Assistant again. i dont exactly know what it is telling me to do? i HAD windows 7 on it but it was a trial version, i was told to make my partion back to mac and then just repartion the hard drive to make it have windows again but it will not allow me to do that and it gives me the above error. what should i do? im not quite sure what it means by "back p the disk and use Disk Utility to format it as a single mac os" any help would be great! thank you in advance!