I use Windows 10 and sometimes the screen goes dim and mouse stops working, I can see the cursor moving, but all the clicks just go "ding". Meanwhile, keyboard is still functional, and if I kill the MusNotificationUx.exe process all things go back to normal. Is there a way to determine why this happens?
2 Answers
This process is Windows Update saying that updates are available. It locks your screen until you click the "Get updates" button, and there's no other option available (you can actually also click esc, but the result will be the same as the result of clicking the button). Unless you have a second screen and a Task manager open on that screen, it's pretty much a pain to kill.
So, you have a problem with windows update unable to display the messagebox (Maybe you uninstalled a bit too many windows 10 core components.)
As for a flawless solution, I don't know any yet.
Security Warning: The "solution" that I'll show may broke Windows Update. While it is reversible without any difficulty, you may get error messages sometimes, and you might need to reverse it once in a month to get the updates. Everything may also work just fine.
You may need Windows 10 Pro, I never worked with the Home edition.
That being said, let's just prevent Windows from acessing that program.
Deleting it is out of question. 1) It's not reversible. 2) Windows may recreate it.
It's located in the system32 folder. Just take a look at the Properties -> Security -> Advanced -> Change owner. Make it yours. Then, you will be able to change who can access it, in the same Security panel, and deny authorisations for System and TrutedInstaller. (Just deny them all, to be sure). Do not deny yours or Administrators access. Instead, be sure to have total control over it.
Now, Windows can't run the program that blocks the screen, which may have unintended consequences, but shouldn't affect anything outside Windows Update.
6If you want to block MusNotificationUx.exe for an account under supervision of Windows 10's internal parental control, it might be useful to know that it is "easy".
Actiate any switch necessary for windows 10's parental control.
Run the said program on that account for at least one second.
Then wait 1 day (maybe less; and at most 8 days; after 14 days I am sure it is no more available), then login on family.live.com with adminstrative account, and select, inside the recent activity, to block MUSNOTIFICATIONUX.EXE.
All of this can be applied t oblock any other program, games included.
