If I use that option, always the help dialog pops up. The help itself
(see screenshot) only knows about "--shared", but not "--shared=no".
If I run
basic-miktex-2.9.6161-x64.exe --user-install=C:\MiKTeX --auto-install=yes
the installer starts, but asks for installing for everyone. But I'd
like to have it for me only. Further, the suggested installation
directory is in %APPDATA% and not in C:\MiKTeX.