This video will show you how to do a clean install of OS X Yosemite from USB.
I have had a few people from the 123myIT YouTube channel ask me how to Fix GPT Error: Windows cannot be installed to this disk.
If you have followed the video linked above and still having some problems getting Windows installed on your Mac because of the GPT partition it is probably best to do a clean install of OS X Yosemite and this video will help you achieve this.
You will need to Create a bootable OS X Yosemite installer USB drive, this drive will install OS X Yosemite on to your Mac.
Make sure you back up your Mac with Time Machine, because the OS X install will remove any data you have on the Mac hard drive. Once you have everything backed up use the newly created USB drive to do Clean Install of OS X Yosemite.
Boot into the USB driver and format the Mac hard drive with Disk Utility. At this stage all of your data with be removed from the Mac hard drive and you can then proceed with the install. Doing a clean install of OS X Yosemite will take around 30 mins to 45 mins depending on the speed of your Mac hardware. Your Mac will also restart a few time during this stage. Just let it do its thing. Once the Mac OS X Yosemite has been installed you will need to setup the Mac as if it is a new Mac. So you will need to choose a user name a password, choose time zone and location.
If you want to know more about the OS X Yosemite you can find more info on the official Apple web page here.