There is something wrong with this part. I'm trying to install Windows 7 x64 and on step 4 I cannot click Next, right after I've formatted the partition with NTFS and I'm getting this:
Windows cannot be installed to this. The selected disk has an MBR partition table. On EFI systems, Windows can only be installed on GPT disk.
bla-bla-bla
I know exactly what I've chosen back when I installed OS X and it was not MBR !!! WTF ?!?
I had the same problem, I'm sure this was discussed somewhere in this thread..
Its been while, but I think in the end I used disk utility to format the drive, then when creating partitions, I didn't create one for windows, I simply left the amount of space I wanted to use unallocated, then let windows do its thing.
Somewhere during the format process, disk utility creates it as an MBR hybrid, I think if you try using NTFS with 3rd party software it might work, anything but fat.
You'll know more than me of any terminal commands to look for an MBR partition on the drive.
Sorry I can't help more, I know a workaround was found though as I managed it a few times.
*edit
I think the thing is, if its ever had a partition created as FAT32 etc, the MBR is still there unless the whole drive is formatted, or you have a way of seeing that mbr partition, perhaps in linux? and removing it.
7. Can't install Windows UEFI because it says this is a MBR drive
If you use Disk Utility to create a FAT partition, your drive will be converted to GPT/Hybrid MBR. To fix this, delete or reformat that FAT partition to Mac OS Extended, or use gdisk in Linux usb to convert your drive to GPT/Protective MBR.
I could be wrong, but I don't think just formatting the partition would work, might need the whole disk to be formatted as the mbr would be protected? gdisk in linux is your best bet Im sure.