Are you able to run a packet capture (either using wire shark on the machine) or on the switch to see what's happening.
What are the proxy server settings on the machine? (Set to auto configure might do some thing a bit weird if the primary DNA domain is set a bit weird).
Yeah, Windows. I run a FOG server so I have an image I can push out in about 45 mins. The image is fully updated and has all the necessary software and drivers needed. Wasn't worth investing any more time when I have that in my back pocket.