[SOLVED] Can\'t install Windows 7 on UEFI Class 3

Hey guys! I want to install Windows 7 on my Mac Pro 5,1 but the install just wont boot. I am using OpenCore bootloader as a boot menu to have a boot screen on macOS or load GRUB. The graphics card I have built is an RX 580. I have tried using a guide on youtube (look up install windows 7 dism method) to install Windows 7 and make my own installer ISO using Integrate7 but none of these methods worked. Is there a way I could end up with a working windows 7 install?


you need this - https://github.com/manatails/uefiseven

Ok, I will try that method. I’ll get back to you if it works.

won’t work, stuck at starting windows @infuscomus


contact the developer on github, they should be able to help you.

found out why it doesn’t work, it fails to unlock the C0000:CFFFF address space. the issue lies in the graphics card vbios.

EDIT: doesnt necessarily have to be the vbios

hmm, I could just patch the vga address in the source code.

does anyone know where the vga rom address space is located? I tried 0x80000 but it did not work

EDIT: successfully patched the uefiseven driver, thx for showing me that tool :smiley:

Hi @formerlychucks
Thanks or the post and letting others know that this is fixed. However it looks like the fix is a customized one. May I request you to please add what you did? Where did you patch or hardcode the address and how you rebuilt the module? This may help others facing similar issues in future.

@formerlychucks How you patched the UefiSeven in order to successfully boot Windows 7, Vista and Server 2008 (R2) in UEFI w/o CSM?

Can you please say how you patched it? everytime i try to find a way to fix this problem i always find people that either weren’t able to fix it or they fixed it but didn’t share the solution, i just gave up on a laptop i had but if you tell me how to fix that problem then i will try to install win 7 back on it.