AFAIK, Windows Desktop OSes do not support XIP.
Only Windows CE does.
A while ago I have came across one old article (06/27/01) on the Net that were talking about the next version of NTe - XPe
Funny thing that they mentioned that XPe will have XIP support. http://www.iapplianceweb.com/story/oeg20010627s0042.htm