i tried writing the file "NetBSD-9.0-amd64-uefi-install.img.gz" to another USB Stick using 'Rawrite32' v184.108.40.206 from a Windows PC, that did not work in my PC either.
But, both of the USB Sticks (the previous one, and the new one) Booted OK in that (Windows) PC.
So, both Boots fine on that PC, but either does not work in mine - an issue with my UEFI firmware?
A little about my system: Gigabyte motherboard, intel Sandy Bridge CPU, American Megatrends BIOS (UEFI).
it's a pretty old system, so NetBSD probably should have good support for my hardwares.
i do not think i've configured the BIOS wrongly, because all the Linux amd64 OS runs fine in UEFI + GPT.
Does NetBSD 9.0 amd64 has any known issues with American Megatrends BIOS?