http://blogs.technet.com/james/archive/2006/08/31/452730.aspxI just found an excellent, excellent, excellent post by Long Zheng which explains the complicated beast which is Windows Vista version branching . He listened to a pod-cast by Sven Hallauer, Director of Release Management for Windows Vista and interpreteden-GBCommunityServer 2.1 SP1 (Build: 61025.2)