title: Having problems installing Ruby on Rails
body: <p>When I try to install Ruby on Rails via <code>gem install rails</code>,
  I get the following error:</p>
  
  <pre><code>C:\Ruby193&gt;gem install rails
  Temporarily enhancing PATH to include DevKit...
  Building native extensions. This could take a while...
  ERROR: Error installing rails:
         ERROR: Failed to build gem nativ extension.
  
     C:/Ruby193/bin.ruby.exe -r ;/siteconf20150202-6216-3lwzut.rb extconf.rb creating MakeFile
  
  make  clean
  'make' n'est pas reconnu en tant que commande interne
  ou externe, un programme executable ou un fichier de commandes.
  
  'make' n'est pas reconnu en tant que commande interne
  ou externe, un programme executable ou un fichier de commandes.
  
  make failed, exit code 1
  
  Gem files will remain installed in C:/Ruby193/lib/ruby/gem/1.9.1/gems/json-1.8.2 for inspection.
  Results logged to C:/Ruby193/lib/ruby/gems/1.9.1/extensions/x86-mingw32/1.9.1/json-1.8.2/gem_make.out
  </code></pre>
  
  <p>I've been unable to figure out the cause of the problem or a solution and any help would be greatly appreciated.</p>