traveltux replied to mpalomba3's topic in Boot CampHi Guys Thanks so much for these posts. It's saved me so much time and frustration..! I ran into the same issues with a 5K iMac Retina with 3TB Fusion drive trying to install Windows 10. I first was unable to create a Windows USB install disk through Boot Camp Assistant (failed on downloading the Apple Support Software). Eventually found the Boot Camp drivers here and had to use a Windows 8.1 machine to create USB install disk with Rufus and then copy the drivers/folders to the USB stick afterwards. When formatting the Boot Camp disk in the Windows installation screen to NTFS I first got the message "Windows cannot be installed to this disk. The selected disk is of the GPT partition style." I then found out that when reformatting the Boot Camp to an exFat format I might progress further but then got the error as described by mpalomba3. As I had already had run the Boot Camp Assistant creating a partition, I had to do the following before achieving a successful Windows 10 installation: 1. Remove Boot Camp partition with Boot Camp Assistant 2. Reboot and do a PRAM reset 3. Create a new Boot Camp partition with Boot Camp Assistant and let Boot Camp initiate the Windows 10 and Boot Camp Software install in Windows 10 4. Update the Boot Camp Software to the latest - this resolved an AMD Radeon R9 M290X 2048 MB Graphics Card issue where Windows wasn't using the highest screen resolution Cheers!