ok i was looking around the net and ran accross this
http://msdn.microsoft.com/embedded/basicly this is whats used ( ok most use a CE version ) in cash registers , those booths that you can convert digital camera cards to real photos in stores , etc .. the idea is that you can take an os ( XP in this case ) and strip out all the user interface , this includeds the desktop ( explorer.exe ) , mouse , kb , etc etc .. but you leave all the dll's and directx stuff in , then you add your custom interface , in our case it would be a front end ...
anyway i thought this would be cool in a cab .. problem is that it takes an expert in programing and a hefty licence to M$ ... but it was a nice thought.