I got a lovely new 21.5-inch iMac with Retina 4K display this week, bumped up with a Core i7, 16GB RAM, and a 512GB Flash drive I previously had Windows 10 installed on my old 21.5" iMac, which was a 2011 model (the last of the "fat" ones before the 2012 slim down). I installed it using Boot Camp 5.something (whatever the latest version was before Boot Camp 6). I tried last night to use Boot Camp 6 to install Windows 10 on my new iMac, and it just won't work. I understand that according to the Boot Camp page at Apple.com, the new "Late 2015" 21.5" and 27" iMac models are not listed as being compatible (with *any* Windows, not just 10). I had hoped that was just because the page hadn't been updated yet... but maybe that's not the case. The first time I tried BCA6 last night, it got as far as the actual Windows installation, but the Windows installer then refused to install Windows 10 to the Boot Camp partition, even though I had used the installer to format it, as the instructions tell you. I ran BCA6 again to remove and recreate the partition, and tried again... this time I didn't even get as far as the Windows installation - BCA6 errored out, complaining that it could not download the support software. Tried again... same thing happened. Any ideas? Should it work, and something has gone wrong, or is it that it really *is* not yet supported?