No issue with Windows 10 Pro Version 1703 OS Build 15063.540. Successfully installed and run

• Erlang at D:\Program Files\erl20
• Elixir at D:\Program Files\elixir\1.5.1

Steps:

• Installed OTP 20.0 Windows 64-bit Binary File from https://www.erlang.org/downloads to D:\Program Files\erl20 (D:\Program Files\erl9.0 was the default probably should have just left it).

• Added D:\Program Files\erl20\bin to the Path under User variables to make sure that any process could pick it up (see here).

• Verified that Erlang worked in a new command prompt.

  C:\Users\name>erl
  Eshell V9.0 (abort with ^G)
  1> io:fwrite(“Hello world!~n”, ).
  Hello world!
  ok
  2> q().
  ok
  3>
  C:\Users\name>

• Created a new ex-setup folder under Documents (a user folder that was moved to D: after creation of the user profile that itself still resides on C:). Moved the elixir-websetup.exe from the downloads folder into ex-setup. Double-clicked it to start the download. Selected version 1.5.1 and checked “Defer installation (advanced)” which created elixir-v.1.5.1-setup.exe.

• Double-clicked elixir-v.1.5.1-setup.exe to start the installation. Confirmed the Erlang installation location. Customized the install location to D:\Program Files\elixir\1.5.1. Opted to let the installer add the file paths to the system variables (so I could remove the one I added manually for Erlang).

• Verified installation in a new command prompt

  C:\Users\name> iex
  Interactive Elixir (1.5.1) - press Ctrl+C to exit (type h() ENTER for help)
  iex(1)> IO.puts “Hello World”
  Hello World
  :ok
  iex(2)> Terminate batch job (Y/N)? y
  C:/Users/name>

FYI: that error can simply be the result of creeping system instability.

With Microsoft systems lots of stuff that is possible isn’t necessarily considered safe. For the longest time, moving anything but the visible folders under a user (Documents, Music, Pictures, Videos) was considered an unsupported configuration by Microsoft (however aggravating that may have been).

… absence hasn’t made my heart grow fonder of Windows in the least.