Windows has had a mechanism called Windows Resource Protection[1] for a long while now, if you delete notepad.exe (I guess nowadays that file isn't even deletable), after a few seconds it will reappear again. If you delete edge.exe (or whatever it's called) or replace it with a copy of, let's say firefox.exe, the WRP will see the file has been removed/modified and restore it, because somewhere inside C:\Windows there's a backup copy of the files..
