Flash Win11 ISO to USB on Mac

install_boot_usb.md

Bootable Windows USB on Mac

Using sudo dd will NOT work for Windows installers.
You will hit the “install driver to show hardware” screen when booting the USB.
The following commands correctly create a working Windows 10/11 installer on macOS.

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1. Identify the USB Drive

diskutil list

2. Format the USB (example: disk2)

diskutil eraseDisk MS-DOS "WIN10" GPT /dev/disk2

3. Mount the Windows ISO

hdiutil mount ~/Downloads/Win11_25H2_English_x64.iso

4. Copy Files Except install.wim

rsync -vha --exclude=sources/install.wim /Volumes/CCCOMA_X64FRE_EN-US_DV9/* /Volumes/WIN10

5. Install WIM Tools

brew install wimlib

6. Ensure Sources Directory Exists

mkdir -p /Volumes/WIN10/sources

7. Split install.wim (takes several minutes)

wimlib-imagex split   /Volumes/CCCOMA_X64FRE_EN-US_DV9/sources/install.wim   /Volumes/WIN10/sources/install.swm   3800

8. Eject the USB

diskutil eject /dev/disk2

Your USB is now ready to install Windows 10/11 in full UEFI mode.