I know, normally Win PE is the tool of choice too bootstrap a WES 7 / 2009 installation. It is a great tool. But, there are occasions, where you run into the limitations Microsoft has built into Win PE.
For example there is no way to share a folder, to run a Windows Installer based setup or to use a .NET application on this maintenance OS.
If your embedded device will be running WES as its main OS, there is help. It is perfectly OK to tailor a small WES utility image for maintenance purposes fitting your demands and to use it to boot the system in a factory process for deployment or testing.
If you have doubts, go and check with your preferred licensing specialist! 🙂
BTW. I still firmly believe that great licensing must not require a dedicated specialist.
But this is a different story….