All the following steps will happen in a terminal
You will need:
- USB drive (min. 8GB)
- Windows ISO of your choice
1/ Install Homebrew
/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
2/ Install Wimlib
brew install wimlib
3/ Find the disk identifier associated with the USB drive you want to use
diskutil list external
4/ Format the drive using the MS-DOS format
diskutil eraseDisk MS-DOS "WINSTALL" MBR disk6
5/ Within the terminal, navigate to the folder where your Windows ISO is and mount it
Adapt the ISO name to match yours
hdiutil mount Win11_22H2_EnglishInternational_x64v2.iso
6/ Copy the content of the ISO into the USB drive, bar the install.wim file
rsync -avh --progress --exclude=sources/install.wim /Volumes/CCCOMA_X64FRE_EN-GB_DV9/ /Volumes/WINSTALL
7/ Use wimlib to split install.wim to fit on a FAT32 drive
wimlib-imagex split /Volumes/CCCOMA_X64FRE_EN-GB_DV9/sources/install.wim /Volumes/WINSTALL/sources/install.swm 4000
8/ Once that's done, unmount your USB drive
diskutil unmount /dev/disk6