According to Microsoft, you can split
install.wim into multiple
install*.swm files, so they can fit in a FAT32 volume.
Here are the steps (assume your USB drive is mounted on
Install 7-Zip and wimlib, an open-source alternative to Microsoft's DISM.
brew install p7zip wimlib
Remove the half-copied file
install.wim from the ISO to somewhere else.
7z e Win10_1903_V1_Germal_x64.iso sources/install.wim
install.wim into two parts, each part roughly 3 GiB.
wimsplit ~/Downloads/install.wim /Volumes/USB/sources/install.swm 3072
If you are on Windows, you can use DISM instead of wimlib:
Dism /Split-Image /ImageFile:C:\Users\Admin\Downloads\install.wim /SWMFile:D:\sources\install.swm /FileSize:3072
If you are on Linux, instead of
brew, you can use
pacman, etc. to install packages.