Can't boot from a flash drive created in the Windows installer

[watchmakerful]

Today I bought a used 8 G DDR3 stick and tried to test it.

1. I took an old (but perfectly functioning) 256 M flash drive and installed memtest86+ using the official installer.
2. The official Windows 64 bit installer displayed no errors, but my PC boots straight into Windows even if the flash drive has the highest priority.
3. When trying to boot manually from UEFI, BIOS displays "Missing operating system" and returns to the UEFI interface.
   The only way to start it up was burning an image with GRUB onto a DVD-RW. The test starts up and runs without any errors.
   System: Asus Z87-K, i5-4670K, secure boot in "Other OS" mode.
   Where is the issue?

[debrouxl]

Thanks for the report.

I understand that the old 256 MB Flash drive is functioning perfectly. Nevertheless, have you tried booting:

• with Secure Boot support fully disabled (unless that's what this "Other OS" mode means on your MB);
• some other lightweight OS with UEFI support which can fit onto that drive ?

The USB MSD implementation by firmware, be it on the device or host side, can be finicky. If a tiny distro successfully boots from that drive on your computer, but memtest86+ 6.10 doesn't, then chances are that there's something to investigate, as time permits :)

[watchmakerful]

The official GRUB image (the same one that I used on a DVD-RW) written to the same flash drive using BalenaEtcher boots fine. ср, 26 апр. 2023 г. в 17:29, Lionel Debroux ***@***.***>:

…

Thanks for the report. I understand that the old 256 MB Flash drive is functioning perfectly. Nevertheless, have you tried booting: - with Secure Boot support fully disabled (unless that's what this "Other OS" mode means on your MB); - some other lightweight OS with UEFI support which can fit onto that drive ? The USB MSD implementation by firmware, be it on the device or host side, can be finicky. If a tiny distro successfully boots from that drive on your computer, but memtest86+ 6.10 doesn't, then chances are that there's something to investigate, as time permits :) — Reply to this email directly, view it on GitHub <#7>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ACOPASFXEI37Q53FCE6ILGTXDEWLZANCNFSM6AAAAAAXMQCI34> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[x86fr]

Can you please try with another USB Flash Drive formatted as FAT32?

If it works correctly with another key, the issue probably come from the way your 256MB Flash Drive is partitioned or formatted. Check if multiple partitions are not present, and if it's formatted as FAT16 or FAT32. In last resort, please post the content of the drive.

If it doesn't boot with another key, the issue probably come from your BIOS. Please try with CSM mode instead of UEFI, or check in the boot override menu if you can see your USB Drive Key.

[watchmakerful]

Can you please try with another USB Flash Drive formatted as FAT32?

I'll try it tomorrow.

Check if multiple partitions are not present, and if it's formatted as FAT16 or FAT32

No partitions, the whole drive is formatted as FAT32.

check in the boot override menu if you can see your USB Drive Key.

Yes, I can see and select it, but after selecting I briefly see "Missing operating system" on a black screen, then return to UEFI.