I'm having so many problems trying to install Windows with Bootcamp, I don't really know where to begin. Firstly, my setup: 2015 5k iMac, 4.0Ghz. 32GB RAM, 3TB Fusion Drive, OSX 10.11.2 I tried running bootcamp with a windows 10 ISO from Microsoft and the partition is created and the mac reboots into windows install. At the point at which you select the partition to install, and format it, when you click next it gives an error message "We couldn't create a new partition or locate an existing one". The first time it did this, Windows install created 3 partitions, "Windows Recovery", "EFI", and "Microsoft Reserved". When I booted back into OSX, bootcamp and disk utility both refused to erase and reformat these partitions, so I booted back into windows setup and used that to format them. However they then became unallocated disk space and I lost 500GB of my Fusion Drive as it didn't show in Disk Utility. Long story short, I had to split the Fusion Drive, format both the HDD and SSD, then rebuild the Logical Volume Group, and reinstall OSX. Tried reinstalling windows via bootcamp again, and still get the same partition error message. I've done a bit of digging around online and found that Windows apparently cannot install if there are more than 4 primary disks. When you go through Windows Setup and get to the screen where you chose where to install windows to, the Bootcamp partition is ALWAYS disk 5. Which is what I think is causing the error. How have people overcome this? When I look at the partitions mine are listed as: 1 EFI Boot 2 Macintosh HD 3 OSX Recovery 4 OSXRESERVED 5 Bootcamp The OSXRESERVED partition is the windows install disk, created by bootcamp when you select the Windows ISO. This is where the windows install files come from instead of being put on a USB. However, its getting in the way! I can't delete any of the partitions but I also can't reorder them, and I can't opt to install Windows from a USB. How have people managed to install Windows via Bootcamp at all?!?! I've also tried using Winclone... created the partition and restored from the Winclone image, however when that finishes I get an error saying "Updating Partition Table Failed" and I cannot boot from it. WHAT IS THE SOLUTION!? I really do need Windows on my new iMac. I managed to install it onto my old one just fine. How come there are suddenly so many issues?! HELP!