I have changed all the icons for my project when I export the game to windows. But there is only one place left where the Godot icon remains unchanged. Can someone guide me to change this part as well? How and where do I need to do that? 
thank you everybody so much!
Change Godot icon in properties board Window 10!
See here: https://docs.godotengine.org/en/4.0/tutorials/export/changing_application_icon_for_windows.html
You can also use Resource Hacker.
cybereality I have changed all Cyber, only the properties folder on Windows can't be changed. The only problem left is that. WHY????
You may have to clear the thumbnail cache in Windows.
cybereality Do you mean delete thumnail in Godot Engine or delete outside Window, Cyber?
cybereality It's OK, Master! ^^ Thank you so much!