Windows 11 Bootable USB Creator for Mac M1

A simple Go script to automate creating a bootable Windows 11 USB drive on macOS (Apple Silicon).

What & Why

• What it does

  1. Prompts for a Windows 11 ISO file on your machine.
  2. Lists and validates the target USB device.
  3. Formats the USB as FAT32 with a GPT partition scheme.
  4. Mounts the ISO and copies all files except install.wim.
  5. Splits install.wim into multiple .swm files so it fits on a FAT32 volume.
  6. Unmounts/ejects both the ISO and USB.

• Why use it

  • Automates common manual steps (diskutil, hdiutil, rsync, wimlib-imagex)
  • Ensures proper splitting of the large Windows install image for FAT32
  • Reduces mistakes—fewer copy-&-paste shell commands

Prerequisites

• macOS running on Apple Silicon (M1, M2, etc.)
• Homebrew installed
• Install required tools:

  brew install wimlib

Usage

1. Build the binary

   go build -o win11-usb

2. Run the script

   ./win11-usb

3. Follow prompts

   • Enter the full path to your Windows 11 ISO (e.g., ~/Downloads/Win11.iso)
   • Choose the USB device identifier (e.g., /dev/disk2)
   • Confirm formatting (all data on the USB will be erased)

4. Boot

   • After “Success!”, eject and insert the USB into your target PC
   • In BIOS/UEFI, select your USB in UEFI mode and install Windows 11

Notes

• The script assumes the formatted USB volume will be named WINUSB.
• If your USB device name differs, adjust the usbName variable in the code.
• Always back up any important data before formatting a drive.