hittade detta, Men som andra skriver koppla ur allt, samt avinstallera drivrutinerna för ljudkort etc och starta om så installerar den ju om drivrutinerna och då kanske det slutar bråka.
The advice in this thread fixed my issue immediately. Quoted here in case you find this thread on Google (below is from superuser link):
Apparently it's a driver (Realtek supposedly) problem with Windows 10 that causes this issue, that is, playing a video anywhere (youtube, local file, etc.), pausing, waiting a few seconds, and playing again would result in a volume change without any real change in the speaker volume meter.
The following fixed it for me:
Click start and type sound and hit enter (to open the Sound window). Or you can alternatively right-click on the sound icon in the tray area and select Sounds.
Select the Playback tab and then right-click on the Speakers and select Properties.
Go to Enhancements tab (if you have it) and uncheck Disable all sound effects (or any similar thing you might have in there).