I would like to install Windows 8.1 or 10 on a separate single SSD disk in my MacPro4,1 (not yet flashed to MacPro5,1) using only
EFI/GPT method.
The machine has a 64Bit EFI (rEFIt reports version 1.1 - build 20070328 in the EFI shell using command "ver"), Windows 8 and Windows 10 installer should be downwards compatible from EFI 2.x and should work with EFI Version 1.x as I read somewhere during my extensive research.
Unfortunately the machine freezes after choosing EFI Boot from Windows installer.
I created a USB boot like here https://superuser.com/questions/1045512/how-can-i-create-windows-install-media-that-boots-installs-uefi-only
I tried the same installer and a unmodified DVD ISO on (native, not upgraded) MacPro5,1 and at least came to a blue windows screen with boot error 0xc0000225.
Using rEFIt on a stick, the MacPro5,1 reports the same EFI version and build.
My MacBookPro11,5 boots the stick from Apple Boot Selector Screen and enters setup correctly. When choosing BOOTX64.efi from rEFIt it freezes...!!??
What is funny is that rEFIt reports again the same EFI version 1.1 and build as before on the 2015 Mac...!!
How can I reliably check the EFI version of the machines?
I can get further information through rEFIt if needed. I got access to a native windows machine in the office and I can access command prompt through Legacy BIOS/CMS Bootcamp installation or setup of Windows or boot gparted or use gdisk to modify installers if needed. I can also burn DVDs.
What can I do to get the setup to load in EFI Boot and install Win 8 or 10 on my MacPro4,1?
Thanks a lot for help!