How do you install Elixir? You have to have installed Elixir that was compiled with OTP >= 20, with asdf manager I just use asdf install elixir 1.7.4-otp-20 or 21 for that matter, and don’t have to compile it. It installs binary version compiled under correct OTP version.
Yes, but you can download precompiled binaries that work on windows too from example here: https://repo.hex.pm/builds/elixir/v1.7.4-otp-21.zip it has windows batch files too in there, rest is beam and ex files. And to use it all you have to do is have erlang executables in path so you have werl.exe and erl.exe in your PATH, and to make things easy just add bin from where you extracted archive to your PATH, and voila! it should work. I’m not really sure if elixir installer does anything more than that on windows.
asdf was just an example, and although I have and am using Windows daily I really don’t know what package managers like asdf are there for windows because all my work is on Linux. Extracting archive and messing with path should be easier than compilation on windows, at least I think so.