Installing on Windows for all users does not work if no local administrator is available. The installer will always install for users.
Why?
Because the installer has to do elevation itself if the user calling the installer is part of the administrators group. It cant depend on being elevated from installer start on and having all rights to do everything.
Are you talking about juliaup, which is the recommended way to install Julia?
If so, can you create an issue at: GitHub - JuliaLang/juliaup: Julia installer and version multiplexer
The other question I have: how useful this would be in reality? Because if you install it for “all users”, then no user could install packages, only the local administrator could. Or do I miss something?