Hi,
I was trying to prepare a Windows 10 USB bootable setup Key today.
It was for a uefi system, so I formatted the key FAT32 and copied all the files from the DVD but it stopped with an error about install.wim too big for the support (it was >4GB in size).
I found this nice article explaining how to bypass the issue:
https://win10.guru/usb-install-media-with-larger-than-4gb-wim-file/
To make it short:
- delete all partitions from your usb key
- create a 1GB FAT32 partition
- create another partition with the rest of the space and format it NTFS
- copy all the files and folders EXCEPT "sources" folder, from the DVD to the FAT32 partition
- on the FAT32 partition create a "sources" folder and copy the \sources\boot.wim" file in it from dvd
- copy ALL the files and folders from the DVD to the NTFS partition
this key should be able to boot , the windows setup should appear and you should be able to install windows succesfully, at least it worked in my case
obviously, when I write "DVD" it could be also an ISO files mounted on the PC as source of the files
good luck
and thanks to Kari Finn and Martin aka Cereberus
