Windows PE boot problems

Hello all.

I have a problem with creating a WindowsPE disk.
I am studying 70-685 page 66 creating a bootable WindowsPE medium.
I have gone through all of the text, created the ISO, but it just doesn't want to boot.

Error comes up as missing devices, I really wanted to use the disk with VM workstation to do my work.
Any help would be appreciated, as I really want to get onto the next section.
I want to be able to do it and understand the process before I proceed, I know I could download a file for this, but it is not the same as creating it yourself.

Many thanks.