1) Use any ISO file viewer and open any Windows 7 x64 ISO of your choice.
2) Extract "install.wim" from the "sources" folder within the ISO file to the second USB stick/external HDD/secondary HDD on the target computer.
B) Download "Unlocker" application from here:
410 Gone and copy it to the second USB stick/external HDD/secondary HDD on the target computer.
C) Copy the "bootmgfw.efi" to the second USB stick/external HDD/secondary HDD on the target computer.
1) If you have access to a Windows 10 installation, you find the file here "C:\Windows\Boot\EFI\bootmgfw.efi".
2) If you don't have access to a Windows 10 installation, you have to extract "sources\install.wim" from the ISO image of any Windows 10 installation kit, then open the "install.wim" with 7-Zip and you will find the file here: "\1\Windows\Boot\EFI\bootmgfw.efi".
III) Installing Windows 7 x64 procedure on the target computer
A) Boot the target computer from the created bootable Mini Windows 10 UEFI USB.
B) Partition the install HDD/SSD using diskpart from an elevated (run as administrator) "Command Prompt" window, remember to backup all data first, this will delete everything, using the following commands (where N is your choice for the install HDD/SSD, be careful when choosing):
list disk
select disk N
clean
convert gpt
create partition efi size=100
format quick fs=fat32
assign letter="S"
create partition primary
format quick fs=ntfs
assign letter="W"
exit
C) Let's assume that your second USB stick/external HDD/secondary HDD on the target computer (where you have already copied all the necessary files) has the "Z" drive letter, so just replace the "Z" drive letter in all the following commands with the one of your particular case.
D) Install Windows 7 x64 using DISM and apply EFI boot partition from the installation
1) Apply the "install.wim" image from your second USB stick/external HDD/secondary HDD on the target computer to the "W" partition you created earlier, using the following command entered in an elevated (Run as administrator) "Command prompt" window:
DISM.exe /Apply-Image /ImageFile:Z:\install.wim /Index:1 /ApplyDir:W:\
2) After the process is completed, apply EFI boot partition from the installation, using the following command entered in an elevated (Run as administrator) "Command prompt" window:
BCDboot.exe W:\Windows /s S:
E) Install the modified and signed Intel UHD driver from your second USB stick/external HDD/secondary HDD on the target computer to the "W" partition you created earlier, using the following command entered in an elevated (Run as administrator) "Command prompt" window:
dism /Image:W:\ /Add-Driver /Driver:Z:\Intel /Recurse /forceunsigned
F) Disable the legacy vga (which is incompatible with UEFI) from the registry of the installed Windows 7 from the "W" partition you created earlier, using the following commands entered line by line in an elevated (Run as administrator) "Command prompt" window:
set Services=HKLM\loaded_SYSTEM\ControlSet001\Services
reg.exe load HKLM\loaded_SYSTEM W:\Windows\system32\config\system
reg.exe add "%Services%\Vga" /f /t REG_DWORD /v "Start" /d 4
reg.exe add "%Services%\VgaSave" /f /t REG_DWORD /v "Start" /d 4
reg.exe unload HKLM\loaded_SYSTEM
G) Delete legacy vga driver file (which is incomaptible with UEFI) completely from the installed Windows 7 from the "W" partition you created earlier
1) Install "Unlocker" by running "Unlocker1.9.2.exe" from your second USB stick/external HDD/secondary HDD on the target computer.
2) Using "Windows Explorer", go to "W:\Windows\system32\driver" and look for "vga.sys", right-click on it, and choose "Unlocker". A window appears and under "No action" menu, choose "Delete" and then click "OK". Check manually that the file is deleted. You have to use this method, because you can't normally delete "vga.sys" due to security permissions of the installation.
H) Using "Windows Explorer", copy "bootmgfw.efi" from your second USB stick/external HDD/secondary HDD on the target computer to the following path: "S:\EFI\Microsoft\Boot", overwriting the already existing file.
I) Disable legacy vga (which is incompatible with UEFI) from the EFI boot, using the following commands entered line by line in an elevated (Run as administrator) "Command prompt" window:
bcdedit /store "s:\efi\microsoft\boot\bcd" /set {default} bootlog yes
bcdedit /store "s:\efi\microsoft\boot\bcd" /set {default} bootstatuspolicy IgnoreAllFailures
bcdedit /store "s:\efi\microsoft\boot\bcd" /set {default} novesa on
bcdedit /store "s:\efi\microsoft\boot\bcd" /set {default} quietboot on
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