Boot Camp issue: "The selected disk is of the GPT partition style"


macrumors 6502a
Original poster
Jul 8, 2011
Hey everyone!

I did a fresh install of Yosemite on my iMac (specs below) and with that I obviously wiped my Windows 8 Boot Camp installation. I've set it up a few times before so I had no problems with this. That said, this time I came across a strange issue that I've seen in a few places online yet I can't find a definitive answer or, more important, a reason why it's doing this. I have a 16 GB USB 3.0 Flash Drive and an ISO of Windows 8 (not 8.1) that I created from my original Windows 8 DVD (I had to do this because my iMac obviously has no DVD drive). I usually run the Boot Camp application, locate the ISO, point to the USB, let it format it, choose how much space Windows will have, and let it do its thing. This time, however, it restarts and starts going through the installation but when I get to the screen showing the disk and all partitions it won't let me choose Format on the newly-created Boot Camp partition. The message I receive is "Windows cannot be installed to this disk. The selected disk is of the GPT partition style". I vaguely recall seeing something similar in the past and that it was somehow related to the fact that there was another external drive plugged in. This time, the only USB device connected at this stage is the Windows installer that Boot Camp created. I've seen people mentioning manually creating a partition and bypassing the whole Boot Camp process but surely there's a solution to do it properly. Any advice would be very welcome.

Thanks and have a great weekend!


macrumors regular
May 21, 2014
Try changing the partition scheme using diskpart in command prompt. You can open a command prompt window in the Windows 8 installer by pressing Shift + F10.
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macrumors 6502a
Aug 20, 2014
What I did:

I installed Yosemite from an external drive ( HDU ) to have the internal SSD full accessible.

- In Yosemite install utility create new and empty GUID partition on internal SSD ( to erase everything on that drive )
- Create new GUID partition on SSD ( HFS+, entire SSD size )
- Install Yosemite on SSD and boot it
- Use BootCamp assistant to size and create Windows partition
- Boot Windows setup from DVD ( benutzerdefiniert )
- Format Windows partition
- Install Windows
- Install Windows BootCamp utilities and drivers
- Call Microsoft and explain why it seems that you want to install your Windows license twice, get the solution from them ( telefonisch aktivieren )
- Fertig :)

Happy camper here, everything works as expected.
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macrumors newbie
Jun 13, 2014
Sydney Oz
as you install windows 8, just go to advanced options when it askes for install location. Delete the partition (your bootcamp prtition), recreate it and format it ntfs.