How to downgrade bios

SchneiderEnt

The first twenty or so boards received have UPC1BM0X drivers and I was able to use the bios update to put the 32bit bios on. The last unit received has UPC1D11, when I try to put the old Bios on 32 or 64 bit I get: " 4 - Error: ROM file ROMID is not compatible with existing BIOS ROMID." How do I downgrade or what other options do I have for being able to install a 32bit OS
Thank you for you thoughts

rogertsai(AAEON)

@SchneiderEnt
We did not make a version of 32b for UPC1D11, and I don't recommend you to downgrade bios to UPC1BM0X.
If you can take risks in this case, you can edit the .nsh script file by Notepad, and type /X at the text, e.g /P /B /N /L /X, to avoid check ROMID

karlhm76

For anyone wondering, this seemed to work fine, just have a copy of a 32bit OS ready on a USB, formatted so it will UEFI boot. The pre-installed OS no longer worked.

I used Rufus for that, and a windows 10 32Bit ISO.

I flashed UPC1BM0S BIOS which I obtained from Aaeon FTP site: ftp://data.aaeon.com.tw/DOWNLOAD/BIOS/UP-CHT01