One thing i never understood nor find any easy explanation is how Windows manages changes to system files from differing Windows updates. Take for example
A certain KB release applies patches to A.dll and B.dll, which I may not apply.
A later KB release patches up A.dll only. Which I apply. A.dll should not be carrying the fix in the earlier KB.
When I do choose to apply the former KB fix, what version does A.dll really become? It would seem that Windows Update cannot merely replace files wholesale, but have to intelligently patch the files based on past KBs' hotfixes applied. Correct me if I'm wrong, thanks.