How to install Win7 with an ASRock AB350M Pro4 and Ryzen3?

hello!, im trying to install windows 7 on the motherboard ASRock AB350M Pro4 but im getting an acpi bsod with error A5, is there any way to fix it? thanks!

EDIT by Fernando: Thread title shortened


you’ll want to use a modded acpi.sys driver to get past this A5 BSOD.

32-bit or 64-bit?

@infuscomus hi and thanks for your reply, im using windows 7 64 bit and my motherboard has windows 7 drivers, where do i get this modded acpi.sys driver?


This is the most recent acpi.sys mod version I have - @canonkong might have a more recent version though.

use NTLite to integrate this driver into your win7 64bit boot.wim and install.wim - there should be 2 acpi.sys files in both images - one in \system32\drivers and a backup copy elsewhere (can’t remember where)

remember to turn off driver signing enforcement.

canonkong acpi 64 (145 KB)


Ok, so i just open ntlite, load up the windows install folder, select my desired windows 7 version (i will use professional), go to the drivers tab, integrate this acpi.sys and i also add it to the boot.wim (both setup and recovery?)


If that doesn’t work then you can manually mount the .wim images, open them in windows explorer, browse to the appropriate locations and replace the acpi.sys files by hand.

@infuscomus Ok thanks i will try later if i can and i will tell you if it works.

Did that work tho?