Question Gigabyte GA-Z270M-D3H with latest BIOS won't recognize Rufus-made thumb drive as bootable device

[mrblint]

Problem: can't get Gigabyte GA-Z270M-D3H with latest BIOS (3/9/2019) to even recognize a Rufus-made bootable thumb drive as a valid boot option.

Background: the thumb drive in the retail Windows 10 box has something wrong with it; although it is recognized as a UEFI bootable device by the Gigabyte MB, I cannot boot from it. Nothing happens when I choose that UEFI partition from the boot menu. The Gigabyte splash screen just sits there.

So I downloaded the Media Creation Tool and created a bootable thumb drive. It didn't work either. The system just sits at the Gigabyte splash screen when the choice is made from the boot menu.

So I downloaded Rufus and an ISO from Microsoft and made a bootable thumb drive. But I cannot find a combination of BIOS settings that result in it being recognized as a valid boot option. It doesn't even show up. I've tried turning CSM off and on. Tried changing storage options from UEFI to Legacy. (I don't see a "both" option as this ASUS user on the Toms Hardware site reports on his MB: ASUS BIOS refuses to boot from UEFI flash drive w/ rufus).

 

[Calvin7]

Use Rufus to write an .iso file
(minimum size of flash drive: 4GB)

1. Download Rufus. Rufus is a standalone program and does not require installation.
2. Open the Rufus program from where you downloaded it to run it.
3. Select Create a bootable disk using and choose ISO Image from the drop-down menu. Click the disc icon and browse to your Windows .iso file and select it.
4. To ensure the flash drive is compatible with UEFI, select FAT32 for "File System".
5. To create the flash drive with the "Press any key to boot from USB" prompt, select the Create extended label and icon files option.
6. When you are done selecting options, click Start When prompted, confirm that you want to erase the flash disk.
7. The .iso files will start copying to the flash drive (the process can take several minutes). When Rufus is done, close the program and eject and remove the flash drive.

 

[mrblint]

This turned out to be a problem with the AMI BIOS or the MB itself. The USB thumb drive with Rufus-created ISO, when inserted into one of the ports on the MB rear panel, is detected as a bootable device only if there's also a thumb drive inserted into the one of the USB ports on the front of the PC! And even then it cannot boot from the thumb drive it recognizes as a bootable device. I ended up burning an ISO onto a CD and installing from it instead.