Thank you all for your efforts, I finally had to restore Windows (keeping the files), because I did launch another string in Powershell (I can't remember which one) and, as a result, all the built-in...

Thank you, but I already restored Windows...

lorenzo

I tried this code (as indicated in your link) in an elevated Windows Power Shell:
Get-AppxPackage -AllUsers | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register...

Thank you, but it doesn't work.
I tried it before.
The report says: "Troubleshooting coundn't identify the problem".
And then in detailed information, every issue is 'not present' :(

lorenzo

Calendar and Mail app don't work: I click on their icons. Nothing happens.
The system is able to launch Store, I have several app updates that are pending, but when I try to download them I get an...