Z390 Ultimate ASRock BIOS downgrade - AFU is the right choice?

Hello @Fernando
I have a problem. I’m making workstations. As you may have already find out: in last month or so MB manufacturers made BIOSes which cannot be downgraded.
But here lays a problem: those BIOSes are not stable. I have bought two Z390 ASRock Motherboards. I was trying to overclock and the OC fails on 3 i9-9900k with my well known settings.
I had no problems with 1.9 BIOS ( https://www.asrock.com/mb/Intel/Z390%20T…/index.asp#BIOS)
And here comes the main question" Do you think I could overwrite BIOS/UEFI at this platform with AFUDOS under DOS with “/GAN” parameter?
Which version of AFU should I use? Where to get that one?


@ADVenturePO :
Hello Peter,
welcome to the Win-RAID Forum!
Since our BIOS Guru @Lost_N_BIOS knows much more about how to solve your problem than me, you should better ask him for support.
Good luck!
Dieter (alias Fernando)

Hello @Lost_N_BIOS would you be able to help?

Thanks. Peter.

You can downgrade the bios. First you have to download the AFU tools from “https://ami.com/en/download-license-agreement/?DownloadFile=Aptio_V_AMI_Firmware_Update_Utility.zip” also download the “original untouched bios you want to downgrade too from Asrock website”

unzip the all the files you downloaded “Don’t rename the bios file” and use the afuwin tool - unzip that folder and use “afuwinx64” not the GUI version and open a admin rights CMD command make sure you have the bios you want to downgrade to is in the same folder. Type afuwinx64 XXXXX /CAPSULE /P /B /N

it will say at the end “Do you want to restart” You click “yes” it will shutdown the computer. Then you turn the computer back on and it will start “Instant flash” and will downgrade the bios".


@ADVenturePO - I would FPT flash the BIOS region only, the above method may do the same, but I dislike AFU and have only heard bad things mentioned when someone used /CAPSULE flag too (Notice the Use at your own risk warning presented right away)
ME region is the reason you are not able to backflash normally, that’s why they say you can’t downgrade, and possibly microcode changes Intel wants them to enforce too.
But, BIOS region is not usually blocked from FPT flashing, so I’d dump the BIOS region, then have someone (Me) copy out your NVRAM x2 and board specific details in their various locations, and place all that into the stock BIOS region from the version you want, then reflash this via FPT.

Definitely DO NOT use any old AFU that allows /GAN, this is for decade older BIOS than your current and will only = bricked board

Hey @Lost_N_BIOS
What do you mean by:

Could provide link to instruction?
Or is this this one: [GUIDE] Grub Fix Intel FPT Error 368 - BIOS Lock Asus/Other Mod BIOS Flash
If it’s somewhere else please show me where to look for it.

The desired version of BIOS is 1.9 http://asrock.pc.cdn.bitgravity.com/BIOS…te(1.90)ROM.zip

The already implemented version is 4.1 : http://asrock.pc.cdn.bitgravity.com/BIOS…te(4.10)ROM.zip

How can I copy out my NVRAM x2 and board specific details in their various locations?
What files should I provide and with which program should I extract it?

I’m sorry, I’m not up to date with this anymore. :frowning:

Maybe you’ll be able to change files between those two submitted links? :slight_smile:

Thank you.

First - Check BIOS main page and see if ME FW version is shown, if not then download HWINFO64 and on the large window on left side, expand motherboard and find ME area, inside that get the ME Firmware version.
Once you have that, go to this thread and in the section “C” download the matching ME System Tools Package (ie if ME FW version = 10.x get V10 package, if 9.0-9.1 get V9.1 package, if 9.5 or above get V9.5 package etc)
Intel Management Engine: Drivers, Firmware & System Tools

Once downloaded, inside you will find Flash Programming Tool folder, and inside that a Windows or Win/Win32 folder. Select that Win folder, hold shift and press right click, choose open command window here (Not power shell).
At the command prompt type the following command and zip and send me the created file to modify >> FPTw.exe -bios -d biosreg.bin

Directly after you dump the BIOS region above, test flashing it back via this command >> FPTw.exe -bios -f biosreg.bin
If any error stop, show me image of the command entered and error all on same image, do not attempt to move forward

If you are stuck on Win10 and cannot easily get command prompt, and method I mentioned above does not work for you, here is some links that should help
Or, copy all contents from the Flash Programming Tool \ DOS folder to the root of a USB Bootable disk and do the dump from DOS (FPT.exe -bios -d biosreg.bin)

Modifying BIOS like I mentioned is very involved, that’s why I said someone (ME) would do for you. Yes, I will do this for you

That’s a huge jump between very old BIOS and new BIOS, your best bet may be to carry on with BIOS you have now and retweak your OC settings, any time you change BIOS this is always going to need to be done.
Old BIOS is not good, but if that’s what you want we can do. Although, since it’s such a huge difference, there may be a problem with using the old BIOS and the new ME you flashed in, which is much more involved to be able to downgrade.


Do it for me please. What Should I provide 4 u to make it for me?