[Solved] Lenovo G50-80 - Installing Windows 7 on UEFI, the process hangs

Hello
So far I was only a forum reader, today I am writing my first post. I understand something there, but I'm generally a layman in computer matters.

I have a Lenovo G50-80 laptop. There is some Windows 7 x64 on it. I wanted to upload the original Windows 7 Home Premium x64 (for various reasons I do not want ten), not on the BIOS, but on UEFI. I prepared a bootable fat32 gpt flash drive from the original disc image. Boot mode on UEFI, Safe Boot disable. Diskpart clean, convert to GPT. I turn it on, the pendrive works, the first windows initialization bar is loaded, then the black screen with "Starting Windows" and such flying colorful dots of the logo. After a while, the dots freeze. Unfortunately, my pendrive does not have a working LED, but the computer left for about 40 minutes was unchanged. For a trial, I downloaded two other images of the same Windows. Same effect. All the advice I found on the net recommends changing working with UEFI to compatibility mode, but I really care about EFI. I even read that someone advised you to remove one of the RAM chips during installation. Maybe I would try, but I only have one.
Help.

Achrioptera wrote:

. All the advice I found on the net recommends changing working with UEFI to compatibility mode, but I really care about EFI.

Uefi will stay anyway, it's just a compatibility mode, not a change from uefi to bios.

Probably the problem is that the win7 installer does not support USB3 ports. Try to burn the ISO image to DVD and run the installation from there.

So the Legacy and Boot UEFI First mode should be set and it will be fine? So I did not recognize that I already had what I wanted and rummaged everything for no reason? I can accept it, but why does the installation hang?

No USB 3 support. I didn't think about that. In the evening it will try on USB 2. If it fails, it will try the CD.

Edit: on USB port 2 the problem persists.

W7 x64 needs INT 10h \ VBIOS interrupt (emulation) for UEFI boot graphics

UEFI Firmware - Windows support of UEFI wrote:

Windows(R) 7, Windows Vista(R) with Service Pack 1 (SP1), Windows Server(R) 2008 R2 and Windows Server(R) 2008

o Support UEFI 2.0 or later on 64-bit systems. They also support BIOS-based PCs, and UEFI-based PCs running in legacy BIOS-compatibility mode.

o Support on Class 2 systems running in legacy BIOS-compatibility mode by using a CSM, so they can use the legacy BIOS INT10 features .

o Are not supported on Class 3 systems, because these operating systems assume the presence of legacy BIOS INT10 support in the firmware, which is not available in a Class-3 UEFI implementation.

o Windows Server(R) 2008 R2 and Windows Server(R) 2008 also support EFI 1.10 on Itanium-based systems.

so as in this G50-80 is the latest firmware and you tried different paragraphs. including Boot Mode: [Legacy Support] + Boot Priority: [UEFI First], or if there is something about OS like 'Other' (but probably not there) and freezes on the logo



it cannot be installed with the 'normal' way ...

I gave up on Windows 7 and did what I wanted under Windows 10 without any problems.