I'm trying create an USB stick with Windows 7 and Windows 8 installation files.

For that I need move files to different directories so I have the following directory tree:

I have modified boot\BCD file so it shows menu to install Windows 7 and Windows 8 and fixed device and osdevice parameters in it to point to the correct path of boot.wim file

It boots successfully into menu and installation proccess successfully starts but then it stops with an error message saying that it can't find CD/DVD source drive:
a required CD/DVD drive device driver is missing

Any ideas what else I need to modify in order to move installation files into different location?

Thank you.