Windows – Where does Windows 10 store file association

file associationpdfwindows 10

When I create a new local user on Windows 10, the .pdf file associations are inconsistend. According to ftype .pdf files (AcroExch.Document.11) are associated with AcroRd32.exe.
But if the user doubleclicks on a .pdf file, Windows opens it with Edge. Its possible to change the default program on the Windows GUI via properties-open with…, but I need to find a way to do it by commandline. Setting the file associations via GPO as suggested by adobe rules out, since the computer is not member of a domain. I tried HKEY_CLASSES_ROOT\.pdf but this is ignored too.