After the 'big' Win 11 update I lost audio and had repetitive, brief black screens lasting a second or so, then normal screen again.
I tried restarting, disconnecting all perif's, starting then reconnecting; reconnecting them while still off then starting. I went to manufacturer's sites and got their drivers for my Dell tower. Still no audio; still black screens.
This is not a driver problem it is a software problem in the update.
I've now reverted to prior o/s version.
My suggestion is that if you are having the black screen and/or audio problems, don't waste your time re-starting, chasing 'correct' drivers, etc. That isn't the problem - the problem is within the update itself. Go back to your prior setting using 'restore'.