Well, you' d have to go to the windows source code for that. Not really theory, just implementation details I would imagine.
When u save a state, typically u want it to be atomic - as in the "saving" process should only be done if all the stuff that are saved are consistent with each other and won't cause problems. Otherwise, "none" of the things should be done at all. But, it's not always easy I would imagine in an environment such as Windows. We are not talking about a simple database transaction here, where things could be "clearly" grouped together.
So I would imagine, that it just "saves" stuff, and doesn't have time to save "other" stuff to make the whole windows system consistent with each other.