Create Windows 10 USB Installer on macOS

02 Sep 2021

1. Download Windows 10 ISO.
2. Install wimlib:

   brew install wimlib
   

3. Plug in USB drive (>= 8GB).
4. List available disks to get device name (e.g. disk2):

   diskutil list
   

5. Unmount USB drive:

   diskutil unmountDisk /dev/disk2
   

6. Format USB drive:

   sudo diskutil eraseDisk FAT32 "WIN10" MBRFormat /dev/disk2
   

7. Mount Windows 10 ISO:

   hdiutil mount Win10_21H1_German_x64.iso
   

8. Copy files:

   rsync -va --exclude=sources/install.wim /Volumes/CCCOMA_X64FRE_DE-DE_DV9/* /Volumes/WIN10/
   

9. Split the sources/install.vim file to be a bit less then 4GB. This step is necessary because the FAT32 file system limits the maximum file size to 4GB.

   wimlib-imagex split /Volumes/CCCOMA_X64FRE_DE-DE_DV9/sources/install.wim /Volumes/WIN10/sources/install.swm 3800
   

10. Eject USB drive:

    diskutil eject /dev/disk2
    

1. https://www.freecodecamp.org/news/how-make-a-windows-10-usb-using-your-mac-build-a-bootable-iso-from-your-macs-terminal/