B550 Pro-v2 bsod on second stage of win7 install (solved)


1. I managed to get mouse and keyboard working and got through the first stage of windows 7 installation. (None of the usb ports 2.0 or 3.0 on motherboard worked. I installed separate pci-e usb2.0 card and used ntlite to add the drivers to the .wim files.)

2. Now the computer bsods while trying to boot for the second phase of windows installation STOP:0X0000007E

What should i do next? Is it possible to have b550 working with windows 7? Maybe i need x470 or x570 board?

Thanks for any answers, awesome forum and contribution to keep windows 7 alive. Thank you for everything this far.

Some info:
Im on bios
I have the legacy csm options enabled
Processor is 5950x , harddrive is regular ssd

I now think its not possible to install windows 7 with Ryzen 5000 series processor and b550 motherboard. Reading this forum and other forums i think its only possible to use b550 with windows 7 if you have zen2 3000 series processors and the bios is not patched to or over (the patch that starts supporting zen3).

The system will bsod after install. Very similar experiences with other people after trying everything. Only success stories i have read with zen3 are from x570 motherboards. MSI creator and MSI mpg procarbon have been mentioned. (If reader is interested they say asrock x570 are also troublesome because of acpi, also apu processors are very hard)

Today a great success with clean install. I will write more later.

I got the windows 7 installed:

Gigabyte B550 Pro V2 rev 1 , bios is now f13
5950x processor
32gb corsair lpx ram 3600hz, dual 16gb

How i succeeded:
>Windows dvd used was just plain official : en_windows_7_ultimate_with_sp1_x64_dvd_u_677332
>Used pcie usb 2.0 card to get past the install since the motherboard usbs were not working (with external pcie usb card you can circumvent the non working amd motherboard at this time)
>Used ntlite to include the drivers for that card into the usb stick and nothing else was modified (using ntlite is very easy , read the tutorial fernando has and remember to include the drivers in the last step to all the .wims (boot and install too))
>Made image of the modified ntlite windows and used rufus to transfer it to usb stick
>Bios settings to csm

Proceeds to work, audio works out of the box. Only usb 2.0 ports at the moment dont work but havent yet had time to troubleshoot 4x usb 3 ports work. I used canonkongs drivers and this official x470 motherboard chipset driver (AMD_Chipset_Software_Win7_2.17.25.506)

How i made wrong in the first place:
>Bios was not >= so it did not support my processor and i got bsod before the windows 7 installation
>Instead of updating bios at this point i made a mistake and went to update the usb installation stick with canonkong driver set not knowing it would later bsod everything if not done right.
>Then of course i still got bsod and needed to update the bios so i figured that out and did that.
>Got through the first stage of win7 installation
>Next stage it always crashed bsod with 0x0000007E and complaints of all kinds of drivers (because of the canonkong drivers i put wrong)
>Finally tried from a clean windows usb stick with just my pcie card drivers and got through.

Stupid story but maybe someone can benefit from this

TL:DR : Be careful when integrating the canonkong driver set to the windows usb stick installation, it may bsod if not done right as he instructs (he actually says this in one thread) ← try without the drivers (pcie usb card or ps2 mouse/kb way) if you are in a bsod loop