I have a windows 8 pro .iso and I planned on booting it from a flash drive using the only thing I could find possible in which was rEFIt. I have a late 2011 iMac so I have a cd drive in which makes it impossible to boot from a flashdrive but only from the DVD drive. I have no spare DVD's so I will not accept any of those answers. So I got Unetbootin made it bootable and made a partition in disk utility. After I formatted the partition in the installation with nfts, I cannot install as it says I have an MBR disk instead of a GPT. Any help would be appreciated if on subject. Yes I have looked online but I could not find any threads helpful.