I'm currently wrestling with getting Bootcamp installed on a 3TB Fusion iMac. Apparently this is a lot harder than before; I've never had any issues on my previous Macs. I noticed when I was looking at hidden partitions, I have a bunch of extras, or at least what appear to be duplicates, and am wondering why there are so many: Macintosh HD EFI Macintosh HD Boot OS X EFI Macintosh HD Recovery HD Why are there 3 Macintosh HD partitions? The first one is the logical one, 3.11TB. The second is not mounted, and 120GB in size. I'm assuming this is the Fusion portion? The third is not mounted, and comes up as 3TB in size. There are also 3 EFI partitions at 209MB each. I've been reading that the number of partitions you have may have an impact, and that the Windows partition needs to be within the first 2.2TB of the hard drive, and possibly on partition 4 exactly. I'm not having any luck, even when following that criteria. Looking for any insight on the extra partitions -- if they're all needed, or if they were somehow created during my failed Bootcamp attempts, and if any others with a 3TB Fusion drive can chime in on suggestions. I am running 10.9.5 on a Late 2013 iMac. I get to the installation portion of Windows but am always receiving errors that I'm setup for GPT. I've tried both Bootcamp setup from Apple and manual creation of the partitions in a few ways, nothing has worked.