title: Ruby: How to update to Ruby 2.1 in windows? (Installed 1.9.3 using Rails Installer)
body: <p>I installed Ruby 1.9.3, Git, Bundler, Rails 3.2 long ago using RailsInstaller.
  It's pretty easy to upgrade Rails, I can just change it in my Rails' Gemfile</p>
  
  <p>But, How can I update ruby? How can I do it?</p>
  
  <p>I find there is a newer version of RailsInstaller, with Ruby 2.1. But it seems just like an installer, not for upgrade?</p>