While writing my previous post on creating a bootable Windows 10 USB stick on MacOS, I wanted to grab a screenshot of the setup error message that appears when
install.wim is not where Windows Setup expects.
I couldn’t find a way for VirtualBox to boot from a USB storage device, so figured I’d just extract the original ISO, delete the
install.wim and build a new ISO image. I’d then be able to boot this in a VirtualBox VM and get myself a screengrab of the error dialog.
Creating a bootable Windows 10 ISO from the contents extracted from the official ISO image took a fair amount of trial-and-error. I finally settled on the following which seemed to work.
Extract the contents of a Windows 10 ISO to a suitable location, let’s call it
This can be done by mounting the ISO image and copying the contents using Finder,
rsync… whatever your file copying tool of choice happens to be today.
Make whatever custom changes you need to make within
In my case I just needed to remove
install.wimto reproduce the relevant error message.
You’ll need to ensure you leave the
boot/etfsboot.comfile in place if you want the ISO image to be bootable.
Build a new bootable ISO by running the following command
hdiutil makehybrid -o ~/windows_10_custom.iso -udf -iso -eltorito-boot ~/windows_10_custom/boot/etfsboot.com -no-emul-boot -boot-load-size 8 ~/windows_10_custom
The ISO image will be created at
Simple as that. Well, it is when you know how.