Guide - How to install Windows 7 x64 on Acer Spin 5 laptop

Since the owner lounge for Spin 5 is closed, I created a new topic.

See here how to install Win7 x64 on Acer Spin 5:
1) General guide: https://pastebin.com/d4hN4ih0
2) Guide only for i7-8550u CPU: https://pastebin.com/H0cWhQHH

The guide consists in multiple solutions for each step that I gathered around the internet, I only adapted them to the needs.

This guide includes links to all necessary files (including Win7 x64 drivers, hopefully they work with all models, I could only test on mine which is a SP515 with i7-8550u CPU).

The main idea is simple: Acer Spin 5 has an UEFI Class 3 BIOS, which means no CSM. Windows 7's Standard VGA driver needs CSM to operate, so on a UEFI Class 3 BIOS it has to be disabled, otherwise it won't properly boot. But when you do this, you get no video during the installation, because during that the Standard VGA driver is used. Fortunately, there is a way to get video by integrating the integrated Intel graphic card driver so that the installation would automatically load it and get video output, but that happens only after the driver is loaded, so the first part of the installation will remain under black screen. The problem is that there is no official driver for UHD series on Windows 7, so the one for HD series has to be modified to be made compatible with UHD, fortunately that is possible. By modifying the inf file, you always lose the official signature and unfortunately Windows doesn't load unsigned drivers during setup. Therefore in order to get the driver loaded and get video output, the driver must be signed. Officially signing is very expensive and by unofficially signing you have to manually include the certificate into the Windows installation before it even starts to install. Luckily, that is certainly possible by integrating it via it's mounter registry. Some say that using test mode and disabling driver signing might also work, but there is too much uncertainty and something might go wrong and in the end test mode would appear everywhere. More than that, Windows 7's BCD boot files are incompatible with UEFI Class 3 BIOS, so they have to be replaced with those from Windows 10, luckily they match with each other. Finally, activating Win7 under UEFI is unusual, but made possible.