After installing the mod OptiFine, some weird bugs occurred (Buttons didn't get released after pressing, redstone didn't update, comandblocks didn't execute, etc.), so I made a backup of my saves on the desktop, deleted the .minecraft directory and uninstalled the minecraft launcher. Everything worked normally. Then I downloaded the MinecraftInstaller.exe from minecraft.net and tried to run it. First I got a screen to accept the terms of license from Microsoft (A screenshot of the screen is attached to this post.). I accepted the terms of license and clicked on install. A loadin screen showed quickly (Also attached) and then a third screen opened with an error message (Shown below). Then I tried to run the installer as administrator. After the windows password dialog, I got the first screen with the terms of license again and then the loading screen. The progress bar was stuck at 0% and the task manager sayed <1% CPU, around 65 MB Ram, no network traffic and no file operations. I also tried to install the Minecraft Launcher over the Microsoft Store, but the Minecraft Launcher has somewhy a very bad rating there and you have to login with your Microsoft Account to install the launcher and I don't want, that windows connects my Microsoft Account with the system.

The screenshots are in German, so here is the translation:

TermsOfLicense.png:

XBox-Installer

WELCOME TO MINECRAFT

Search for games. Play games. Connect with friends.

Microsoft-software-terms-of-license

[Checkbox] I read the Microsoft-software-terms-of-license and accept them

[Button: INSTALL]

loadingScreen.png:

Xbox-Installer

[Picture of Steve and Alex running out of a cave with mobs]

[Progress bar: For a great experience...]

ErrorMessage.png:

Xbox-Installer

MAKE SURE YOU ARE CONNECTED

Please try then again to update. Windows could not be updated. (0x80131509)

[Button: CLOSE] [Button: Try again]