I came across this thread earlier today because of a problem I've been having getting my WDS build to install the USB 3.0 Extensible Driver for HP Z230 CMT. I tried the DISM GUI app, no luck.
I then followed the suggestion to create a separate driver group. In the past I've been putting all my drivers in a single group per machine type. The driver package was created successfully but the drivers wouldn't load during install.
After creating a new driver package I attempted to add the package to the build and wouldn't you know, the new Package I created was not available. Turns out, by default the attribute window does not filter on USB which is the classification for these drivers. After adding the USB attribute filter the drivers appeared, I added the package to the WIM and all is good in the world. There were so many drivers in the original package that I created I didn't notice that the USB drivers were not being added during the Add Package process.
Hope this helps someone else.
