TL;DR How to install Windows 10 on Mac with Flashed AMD Radeon HD7950 Due to the sheer frustration this installation has been giving me, I caved and decided to ask if any of you can help me with this. I am trying to install Windows 10 on my Mac Pro which was bought maxed out (2 quad core xeon processors, 32GB of RAM, plus a 480GB SSD as the Mac boot drive). Fast forward a couple of years, and I decide to upgrade the GPU for video editing, and found the AMD Radeon HD 7950 (Not the Sapphire/Official version), which was flashed from the seller on eBay to have the boot screen functionality on Mac (the menu to choose what boot drive, recovery mode, etc.). Now to the problem. I burned the Windows 10 ISO to a DVD (couldn't boot AT ALL from "burning" the ISO to a usb stick). After insterting/leaving the DVD disc inside, turning off the computer, turning it back on while holding ALT/Option key, and finally choosing the disc that says "EFI" (black screen as well when choosing "Windows"), the Windows 10 logo would appear for a couple of minutes and then an error would show saying "Your PC needs to be repaired". What's mind-boggling for me is that I tried all of these exact steps on another Mac Pro that doesn't have an upgraded GPU, just the one it came with, and it worked! Windows installed on it and booted and everything! I've come across a few threads about people having very similar issues where they upgrade the GPU (although all of them state that they were using the PC variant of the card without being flashed (losing the boot menu and other things every time they boot up their computer which I use)) From what I could understand from all of these threads is that the problem resides in Windows booting in EFI mode when their card doesn't support it? I just want to run Windows for games, and that's it. Too much trouble trying to use Wine or PlayOnMac while trying to install lots of libraries and such just to play some games (plus many more that aren't supported.) Really appreciate it if someone could help.