[74lobster]

Hi, I'm Cesare and I type from Bologna (Italy) I have a PC with the Windows 10 Pro Insider Preview - Build 21322.rs_prerelease.210220-1651 version installed.
I got a bit confused with the "Movies and TV" app, as I was trying to install the HEVC or H.265 Codec, to see some movies in .mkv format, but something hag gone wrong installing and uninstalling
various codecs, I messed up everything and now, when I try to open any movie, always using the "Movies and TV" app, I see only a black screen with some little rotating circle blue colored,
but the screen remains black and no sound is heard.

Could you give me some help? Do I have to uninstall the "Movies and TV" app and then reinstall it again for resetting all the settings and the various codecs installations I made?
It's probably something I should do with powershell, but I don't even have a clue where to start ...
Could you also recommend me one or more codecs that handle the H.625 video format and the DTS sound format?
I know that there are specifically codecs made for the "Movies and TV" app, but I have no idea what they are and how to install them.
Help !!!

Thanks to those who want help me to solve the problem.