Running a 2012 Mac mini... Previously did Bootcamp during Mavericks with a Win 8.1 ISO on thumb drive, all created and run through BootCamp Assistant. No issues. Just did a clean install of Yosemite, and formatted the drive before hand. Now trying to Redo Bootcamp. The Bootcamp assistant works up until the install process. When it reboots, I get a black screen with "No bootable disc" message. Rebooting again and holding option shows me my OS X volume, recovery, and EFI Boot (the thumb drive). There is no Bootcamp partition shown, and the install is obviously not complete. Booting to the EFI Boot yields yet another road block, as I cannot get passed formatting in the Installer.....When I get to the partition selection/formatting screen it won't let me proceed, when I expand the error message it tells me that partition can't be used because it has a GPT partition table. I am stumped. I am looking to see if anyone has any suggestions, as I've done this a million ways and a million times before, and under Yosemite I can't seem to do Bootcamp.