This creates a bootable Windows Installer device for booting on UEFI systems.

You can use this to make a bootable Windows USB drive.

This is not something I use very often, so don't expect much development.

You need the following stuff:

• zsh
• 7-Zip / p7zip (for 7z)
• fdisk / gptfdisk (for sgfdisk)
• dosfstools (for mkfs.vfat)
• ntfs-3g (for mkfs.ntfs)
• gawk (for awk)

Most distros will have the majority by default.

On Arch Linux you can install all these with:

pacman -Sy --needed zsh p7zip ntfs-3g parted dosfstools gptfdisk gawk

Usage: mkwinimg.sh ISO DEVICE

ISO is the path to the ISO you wish to use.

DEVICE is the path to the device you wish to use. You can use loop devices with this.

Make a bootable USB drive (/dev/sdb) using an ISO:

mkwinimg.sh 'Win10_21H2_English_x64.iso' /dev/sdb

Create an image file for dd-ing later.

truncate --size 8G win10.img
losetup --show -P -f win10.img
# ↑ gives you the name (eg. /dev/loop1)
mkwinimg.sh 'CMGE_V2020-L.1207.iso' /dev/loop1
losetup -d /dev/loop1

To make it as small as possible:

fdisk -l win10.img # multiply sector size by last end sector
truncate --size (result_goes_here) win10.img

To apply it to a device (/dev/sdb here):

dd if=win10.img of=/dev/sdb bs=1M status=progress oflag=sync

This will not work with BIOS/Legacy systems.

You can't make anything of the sort work cleanly with BIOS because the "people" responsible for the Windows Installer are either idiots or (if they broke it on purpose) cunts. I won't elaborate on that.