@Kebicle - Awesome to hear you got it working now!! 
Thanks for your help on this one @bloodhand !!! 
Good to know. Can you post the link to it, maybe someone having the same CPU will need it? Thanks
@zir_blazer
The issue described on the above paper is relative to the OVMF video driver implementation.
On legacy hardware and IRQ the INT 10 (Video Driver) is used to retrieve the VESA_BIOS_EXTENSIONS (VBE) function.
The VBE information block allow to determine the capabilities supported by the display adapter.
A Compatibility Support Module (CSM) is not a requirement for the WINDOWS 7 EFI installer.
A functional Graphics Output Protocol (GOP) produced by an EFI video driver IS.
@zir_blazer
The issue described on the above paper is relative to the OVMF video driver implementation.
On legacy hardware and IRQ the INT 10 (Video Driver) is used to retrieve the VESA_BIOS_EXTENSIONS (VBE) function.
The VBE information block allow to determine the capabilities supported by the display adapter.
A Compatibility Support Module (CSM) is not a requirement for the WINDOWS 7 EFI installer.
A functional Graphics Output Protocol (GOP) produced by an EFI video driver IS.
You are completely wrong on that. CSM being needed to install Windows 7 is a rather well known requeriment:
https://support.microsoft.com/en-us/help…-on-surface-pro
https://docs.microsoft.com/en-us/previou…rectedfrom=MSDN
The whole point is that you CANNOT run Windows 7 in pure UEFI mode, be it either TianoCore/OVMF for Virtual Machines or native use cases like UEFI Class 3 Devices (Or for anyone that disables CSM), since Windows goes nuts due to the lack of a INT10 handler, which is the reason why you require CSM enabled and a VBIOS. The VgaShim is pretty much a small UEFI Driver that provides the INT10 interface that Windows 7 expects in an UEFI only environment. And while it was developed for Virtual Machine use cases, some people did ports intended to run in native, like this one, which is an UEFI executable that has to be loaded before Windows Boot Managers: https://github.com/driver1998/VgaShim
Note that the only W7 component that requires the INT10 handler appear to be the Boot Loader. I have been reading that some people replaces it with the W10 one or some hacks like that, and it seem to work. But it doesn’t work out-of-the-box.
If you disable Standard VGA Driver, of course using the Win10 EFI boot file on the EFI partition, then you can get past that. Of course with a black screen during boot until the specific GPU driver is loaded. For that you must integrate that specific driver in a signed version. If you have an unofficial modded driver, then you might need to sign the drivers yourself and also integrate the certificate into the installation. If you don’t know which driver you need, then it is difficult because you have to literally try every driver, signing, integrating certificate, installing…
I will try myself VgaShim when I will need to reinstall Windows on my laptop. Probably not very soon because I don’t use Windows Update and in case of problems I always have a working backup of the installation with all settings that I restore with Symantec Ghost.
@zir_blazer
It’s a complex argument but like you are pointing out it mainly depend by the bios vendor EFI implementation and how the manufacturer along the CPU platform maker want to target the board for the market.
It take around 3KB of unoptimized runtime code to run a protocol instance and a timer for the legacy environment. CSM is nothing more then a wild non-standard tool of common procedure to boot a legacy installation.
HIGH/LOW in general to speak won’t go away by removing interface or precluding the user access with systematic down-phase or targeted changes.
Hello,
Glad to discover this board. I think someone will reply here.
I posted this on a differernt forum and waited (for a month!) for a reply, only to be directed to an over the top, complex solution! 
I was convinced that something simpler should exist. Then I discovered UEFISEVEN. Now, I am not sure what slipstream is, so I tried to follow the simple steps:
* Rename bootx64.efi at (UsbDrive)\EFI\Boot\ to bootx64.original.efi – OK, done.
* Unpack bootx64.efi from UefiSeven archive and copy it to (UsbDrive)\EFI\Boot\ –now, where is the bootx64.efi file in the downloaded uefi-seven zip file? There is no file like that. How is one to copy it to the USB when this file doesn’t even exist? inside the Uefiseven folder there are ‘C’, ‘H’ kind of files… 
This sure must sound stupid to veterans here, but would really appreciate if people can help. I absolutely hate Win10 and want to run the good old Win 7 on my new laptop.
Thanks!
Hi. Please can someone guide me.
@rsm_21
U mean this: https://github.com/manatails/uefiseven/releases
3 files inside, bootx64.efi, UefiSeven.skiperrors and UefiSeven.verbose
Thanks for replying.
Yes, my bad. I downloaded the source code by mistake; now I’ve the aforementioned program.
However, even after the installation is done, the instructions ask you to enter in the efi folder and change more filenames. How is that possible?!!
On the other hand, I still have system hanging at the windows boot logo/splash screen. Please advise – I will be very, very grateful if anyone helps me install Win7.
I absolutely hate Win10. I’m old school, been using PCs since 2000 (though never a script-level guy or developer).
Please can someone help.
I don’t know how others did, but this is my method. After you installed windows from the usb containing uefiseven, you need to mount the hidden efi partition from the target drive using diskpart. For this you need to boot using a bootable efi win10 pen version so you can have a running windows with gui where you can use diskpart, mount the efi partition and then simply make modifications going to the efi partition in "this pc.
U think you could also preedit the install.wim en boot.wim from the windows 7 installation and make the modifications in windows\efi folder. Therefore when you install windows it makes the efi partition using the folder in windows\efi path. But I didn’t test this.
You could also grab FlashBoot Pro and use it to create a uefi-ready boot usb of win7, see official guide: https://flashboot-v3.prime-expert.com/UserGuide-3.2s.pdf
Thank you so much for replying back.
Ok. I’ll try this. If it only about mouting the target partition and doing edits, then perhaps I’ll do this using Linux. It wil be much more easier that way.
I’ve no thoughts really. I’m kinda stuck; whichever method takes me to Win7 (preferably easier one), I’ll do it.
Yes, the Flashboot Pro is a tool I discovered as well (after my post here), but its 3.x versions are not freewares. The freeware version doesn’t have this option! Otherwise, the Flashboot method would’ve been the easiest.
So I tried the methods suggested by bloodhand (many thanks!), but still get nowhere. I still end up with one or the other blue or black screen of death. The system just doesn’t boot. If anyone knows of any other methods, please advise.
The simplest, and probably the best, method is probably to use a custom ISO, but that doesnt’ seem to exist AFAIK.
Thanks again.
Unless the OP has anything to add, request mod(s)/admin(s) to close this thead. My query is answered.
Thx.
I d like dual boot with Windows 7 and Win 11. But Win 11 needs full UEFI and i don’t want switch these in bios every time for different OS. Can i somehow install Win 7 in such UEFI which will also be good for 11?
@Atom_Ant
You should be able to leave CSM on to boot windows 7 and still have windows 10 or 11 boot in full UEFI mode.
Just use F11 (or whatever your system uses) to select which drive to boot from.
Hi, im having the same problem, i cant install windows 7 on my uefi only laptop, when i boot to the usb the screen just hangs at “Starting Windows” so what i did is to apply the install.wim from windows 10 on another partition (because i have windows 10 installed on the pc right now) but i got an error about a bitlocker key, so i searched in windows 10 and a function called device encryption was on, i disabled it and i got rid of that error but now im stuck at the error 0xc0000098 when i select windows 7 from the windows bootloader, i searched online and i tried using a project called vga shim and uefi seven but both didn’t work, they said unable to unlock memory at 00000 bytes or something, so then i tried following this guide:
http://reboot.pro/topic/21108-install-wi…l-gop-hardware/
but my laptop does not have windows 7 drivers, and i couldn’t find modded drivers online, the laptop model is Asus rog strix g713qe, it has an amd ryzen 5 5600h and an rtx 3050 ti gpu, i really want to install windows 7 but im trying from 4 days with no success.