Installing Windows 7 on the pure UEFI systems without CSM

Discussion in 'Windows 7' started by PrimeExpert Software, Jan 2, 2020.

  1. Muffin Top

    Muffin Top MDL Member

    Jun 12, 2025
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    Thanks, I'm likely to end up doing this. I just got side-tracked by trying to figure out if Dell/Intel's GPU driver would allow me to have video without CSM.

    I heard it boot into windows without CSM, but of course the VGA driver doesn't work without CSM.

    I go to Dell's website, and look at the drivers they offer for Win 7, yet I've been having a bit of difficulty getting their driver onboarded into my system. I'm hoping my difficulty with their driver stems from having installed the Win 7 install.esd via a Win 10 USB. This methodology temporarily caused my Ultimate image not to be recognized upon installation. Maybe gaining access to the rest of my system resources via fixing the branding issue might allow my system to use Dell's Win 7 driver?
     
  2. TK50P

    TK50P MDL Member

    May 29, 2023
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    how did you got it worked? I also tried flashboot pro 3.3t, but no luck for me. I mean, i could boot with flashboot flashed USB, but GPU doesn't work. GPU is AMD Radeon RX 5700 XT btw.
     
  3. Muffin Top

    Muffin Top MDL Member

    Jun 12, 2025
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    I believe flashboot pro does not support UEFI without CSM. Did not work for me, and he did not respond to my inquiry.


    As far as I understand it, your options are (1) UEFI7 or (2) find a graphics card with Win 7/8 drivers. I'm doing the latter, because I haven't learned keytools yet, which I'm assuming would be required to secure-boot UEFI7 (because it modifies the bootloader).
     
  4. EFL

    EFL MDL Junior Member

    Jun 28, 2025
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    What's your platform?
     
  5. Alexandros C. Couloumbis

    May 19, 2018
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    if you study carefully both relative threads, you will probably conclude differently

    finding (working) GPU drivers for contemporary hw is a whole different issue, and probably a more challenging one, than booting win7 under UEFI class 3

    all mentioned projects remain Work in Progress which is fueled mainly by the feedback and the enthusiasm of the community

    best of luck in your quest
     
  6. Muffin Top

    Muffin Top MDL Member

    Jun 12, 2025
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    Optiplex 7050. It's user-friendly for taking your time about setting it up for secure-boot, because back then they still included CSM in the firmware GUI, so you can play around with it until you're ready to secure-boot.

    Flashboot pro has an impressive website. An obvious observation is that if it could secure-boot Win 7, then he would explain how to set it up (so you're not relying on my experience).

    I think the forum has concluded that it won't work to backport native Win 8 drivers to 7, so the only alternative to UEFI7 is a graphics card (i.e., third-party driver, since MS never made theirs backportable).
     
  7. Alexandros C. Couloumbis

    May 19, 2018
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    #527 Alexandros C. Couloumbis, Sep 7, 2025
    Last edited: Sep 7, 2025
    have a look here, although for RX5700XT you may be out of luck. it doesn't hurt to try though
     
  8. Alexandros C. Couloumbis

    May 19, 2018
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    ++
    talking about backports there is also this initiative (still a proof of concept so far)
     
  9. EeroS

    EeroS MDL Senior Member

    Jul 28, 2018
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    Time to bump this thread up, and write something on this forum after a long time:)
    Has anybody tried to install Windows 7 on newer Surface machines? I tried on my Surface Pro 5, but faced the ACPI compliance BSOD. Tried many different patched acpi.sys files, but nothing helped. Using UEFISeven to get display working. Should I try Flashboot Pro?
     
  10. UsefulAGKHelper

    UsefulAGKHelper MDL Senior Member

    Aug 28, 2021
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    First, what kind of hardware do you have? Just so we know.
     
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  11. ibay770

    ibay770 MDL Member

    Oct 9, 2015
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    I tried to install with my SP3. Same issue. FP, just fixes the frozen logo, havent yet found a solution for the A5 error
     
  12. Muffin Top

    Muffin Top MDL Member

    Jun 12, 2025
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    If you got the display working with UEFI 7, and can turn off CSM, then you should be good to go. To enable secure boot, you'll have to enter the modified bootloader's SHA into the firmware.

    This would be a lot more complicated with Flashboot Pro, which re-writes more files.

    By contrast, UEFI 7 is a relatively straightforward modification of your boot set-up, so you can enter the modified file into the firmware and begin secure-booting.
     
  13. EeroS

    EeroS MDL Senior Member

    Jul 28, 2018
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    It's a base spec model, with Intel Core m3-7Y30, HD 615 iGPU and 4 gigabytes of RAM.
    And of course Microsoft's own EDK2 UEFI, without any CSM legacy options.
     
  14. PrimeExpert Software

    Dec 3, 2019
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    #534 PrimeExpert Software, Nov 10, 2025
    Last edited: Nov 10, 2025
    (OP)
    As a developer of FlashBoot Pro, I'm definitely sure you should try FlashBoot Pro. :)

    On a more serious note, I have exactly this hardware (Surface Pro 5 from 2017) and managed to install Windows 7 on it. Here are my ups and downs:

    • ACPI problems are very real on this Microsoft hardware and they are caused by Surface DSDT ACPI table which refers to an I2C resource. There is an embedded controller which manages battery changing and other things in Surface Pro, connected to main CPU via I2C bus, and this connection is technically described by the ACPI tables. Windows 7's ACPI.SYS does not support this kind of thing and can't handle I2C resources, hence the BSoD. These new ACPI bytecodes can be patched out of ACPI tables, and FlashBoot Pro has an undocumented feature: sideloading patched ACPI tables from ACPITABL.DAT in EFI system partition, so you can sidestep that hurdle, but after doing that, battery charge indicator in Windows 7 does not work. You will not know the charge state of your battery in Windows 7 on this tablet.
    • Intel integrated GPU works fine, there are compatible drivers for Windows 7, Aero theme is functional, touch screen works too, some lightweight 3D games run too (e.g. Volume by Mike Bithell Games)
    • nNVMe SSD works fine via generic NVMe driver
    • builtin audio works fine with mainstream Intel HD-Audio driver for Windows 7
    • keyboard with touchpad (Surface Type Cover) works fine with generic Windows 7 USB-HID drivers, it's just a multi-function USB device from software point of view (keyboard + mouse)
    • builtin WiFi does not work at all (nominally it's Marvell chip, but it's debug symbols are hosted on Microsoft symbol servers, so this driver is built by Microsoft from source code, so I would say it's de facto Microsoft chip). Hence, there are no compatible drivers for Windows 7, Windows 8 driver reads regulatory domain and something else from UEFI variables, relies on new power management features -- heavily depends to the new Windows 8+ kernel API. You will have to use USB WiFi dongles if you want to run Windows 7 with WiFi on this hardware. USB-to-Ethernet dongles work fine too. But there is just one USB port available on Surface Pro, so you need a USB hub to connect anything else (mouse, USB thumbdrive etc).
    • SecureBoot can be disabled in BIOS/UEFI setup. I've set up rEFInd bootloader to dual-boot with Ubuntu on my Surface Pro, it's not signed by MS and has no signed shim, so it was easier for me to disable the whole thing rather that wrestle with MOKUtil etc.

    In short, it's doable, just not very ergonomic on this harware (without battery charge meter, without bultin WiFi and always with connected USB hub). If you decide to go this route, drop me a line with your ACPI tables at [email protected] and I will patch them (provide you with ACPITABL.DAT) so you can sidestep ACPI_BIOS_ERROR BSoD in Windows 7 setup on this hardware. You can make a dump of ACPI tables with RWEverything under Windows 10/11 (or Windows 10/11 ToGo).
     
  15. EFL

    EFL MDL Junior Member

    Jun 28, 2025
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  16. ibay770

    ibay770 MDL Member

    Oct 9, 2015
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    Perfect, thank you.

    Will give that a shot with my SP3 and send the appropriate files. Perhaps you can add a patcher to do this automatically while prepping the iso..
     
  17. UsefulAGKHelper

    UsefulAGKHelper MDL Senior Member

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    Sorry for intruding but regarding the Int10h emulation, have you seen CSMWrap (by FlyGoat)? It's an .efi application that uses SeaBIOS's csm module and Seavgabios to emulate a legacy bios as a replacement for CSM in uefi class 3.

    Maybe looking up in that code as reference will make it easier for you to improve FlashbootPro's emulation?
     
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  18. Muffin Top

    Muffin Top MDL Member

    Jun 12, 2025
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    Thanks for developing this intriguing product. Is it possible to assist novices by developing a short list of files that need to be entered into the BIOS to enable secure-boot?

    I was not able to secure-boot via FlashBoot Pro. I just assumed as a novice it would be too difficult for me to let the BIOS know which files are safe to enable secure-boot.