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I have a machine with UEFI firmware [Asus UEFI firmware version 3202] that previously ran Windows, later Ubuntu, that I now plan to install Windows 11 on, but the Windows 11 install media will not boot.

I have downloaded the Windows 11 ISO and written that to a USB stick using dd in Ubuntu, but when I launch the EFI boot menu, I get two options for it, however both of them only makes the screen blink black, then takes me back to the boot menu:

  • USB Flash Disk 1100
  • UEFI: USB Flash Disk 1100

When I installed Ubuntu, I needed to change Secure Boot options to "Other OS" but changing that back to "Windows UEFI mode" does not seem to have any effect; Fast Boot is disabled.

How can I get the UEFI firmware to accept my install media and boot from it?

Bex
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2 Answers2

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The UEFI: USB option is the right one. (The one without an 'UEFI:' prefix would boot the disk in "legacy BIOS emulation" mode.)

One possible issue is that ISO images distributed by Microsoft are literally just that, ISO-9660 images meant for CDs/DVDs – they're not made to be written to a USB stick.

CDs/DVDs use a different filesystem than most other kinds of media (either ISO-9660 – hence the name – or UDF) and they store their boot code in a different location than most other kinds of media. When the same image is written to a USB stick, it appears not quite right; there is no MBR bootcode, there is no GPT partition table, there's no FAT32 filesystem. Either the firmware or Windows itself will likely fail to recognize it at some point.

This is different from Linux "ISO" images, which have been run through the isohybrid tool to deliberately create a hybrid CD/HDD image with several different partition tables overlapping each other (as well as Linux itself being a bit more relaxed in regards to what filesystems and what partition layouts it accepts).

The proper way to create a Windows USB stick from Linux would be to create a normal MBR partition table with a normal FAT32 partition, and then to extract the files from Windows.iso into the USB stick. (If this fails due to the Install.wim file being too large for FAT32, install "wimtools" and use the wimsplit tool to split it up into ~2GB chunks.)

grawity
  • 501,077
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Probably your easiest route is to use Ventoy, which is a multi-boot solution.

Once you have installed Ventoy to the USB, you just copy (not burn) the ISOs to it, and it takes care of the boot process.

When you boot Ventoy, it lists all the ISOs on the USB and asks which one you want to boot.

Note that not every UEFI computer is compatible with Windows 11.
See System requirements.

harrymc
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