Hello everyones, I have actually some problems to install Windows Server 2012 in a bootcamp partition and from USB key made with WinToFlash software. Here is the steps I used : - USB install preparation with WinToFlash - reFit installation from package 0.14 - Mac reboot two times - Loaded Windows 2012 Server iso in Daemon Tools - Made Bootcamp partition from assistant - Reboot of the Mac with the usb key plugged. - And then I choose my EFI boot from reFit Menu. - Then, installation launch and I got error at the step of choosing partition The error tells that I could not use MBR partition in EFI mode, and that I must use GPT drive to do so. I saw the nice post of murphychris here : http://forums.macrumors.com/showthread.php?t=1424605 Which is greatly explained, but I feel a little lost of what to do now. Do I have to delete and recreate this partition using gDisk ? Will it have bad effect on that bootcamp partition ? Do I will boot on that partition without problems after Windows installing using that way ? So please tell me what to do. Thanks for help. Regards.