Thanks for the answers...
Drivers shouldnt be a problem, for the WinPE Packages we have 154 driver included, all from the dell site (we are using Dell-Computers).
F8 support ist enabled.
I checked the the network settings in the console, it was really weird...
first it didnt saw the network card, after a short brake i tried again and it showed the right network settings.
Coult it be, that the client is the slow too handle it?