By skyforbes 
Hello fellow sysadmins .
At first I write backstory to my question.
Today I experienced Windows 11 installation broken so much I can't install updates , Audio service doesn't work so no sound , even icons in start menu was missing.
After hour of unsuccessful attempts to repair I got idea : Update Windows from 24H2 to 25H2 . Maybe it will work, I thought.
And it really works , everything was fixed.
Well, now the question is:
what that upgrade did , so suddenly all problems was fixed?
I mean , can I replicate the "operations" which upgrade did "under the hood" , manually without executing the upgrade process?
Because only thing that saves me was , I could upgrade that Windows.