EDIT: This topic has now been blogged in detail here.
Since the dawn of time, Windows PE (WinPE) has not had any support for the 802.1x authentication protocol. This meant that any network deployment of Windows via a network secured with 802.1x was a non-starter, causing headaches for a few on my customers; I actually had one customer that ran new network cables to a majority of the desks in order to be able to deploy Windows XP over the network.
However, thanks in part to a colleague of mine who worked on this, Microsoft has released hotfixes that now add 802.1x support to both WinPE 2.1 and WinPE 3.0. You can get the hotfixes and further information at the below links:
WinPE 2.1: http://support.microsoft.com/kb/975483
WinPE 3.0: http://support.microsoft.com/kb/972831
I wanted to share the links now, but in the near future I will write up a post on how to use these hotfixes in your deployments.
This post was contributed by Daniel Oxley a consultant with Microsoft Consulting Services Spain