WinPC wrote:This build is interesting, because it is one of the very first (if not the first) builds to have the new WIM-based Setup routine, and it was from this point on that Longhorn, for the most part, now used the new Windows Setup, with a couple of occasional exceptions (such as Build 4066, or at least the copy we have here, as well as 64-bit copies of certain builds).
It's the first
main build to use the WIM system (assuming you don't include a potential Build 4000, which no-one knows anything about, including if it even exists). WIMs existed in other labs before then, and there's been more than a few hints that the WIM system might even predate the Longhorn project as part of another, skunkworks MS project (WinPEs certainly do, by a few years).
Prior to the reset, the new system was exclusively x86 (no known x64 or IA64 build at all uses it), and then usually reserved for Professional SKU compiles. From what I understand from others with more builds than you or I, 4028 is the anomaly in the server builds, shipping with the WIM system, rather than 4066.