title: 'ruby' is not recognized as an internal or external command
body: <p>I'm trying to install rubygems on my windows7 pc. I've download the <strong>rubygems-2.4.1.zip</strong> from <a href="https://rubygems.org/pages/download" rel="nofollow">https://rubygems.org/pages/download</a>. Now I'm trying to install rubygems through the command:</p>
  
  <pre><code>ruby setup.rb
  </code></pre>
  
  <p>But I see the error:</p>
  
  <pre><code>'ruby' is not recognized as an internal or external command
  </code></pre>
  
  <p>How can I use 'ruby' command on my pc?
  Downloaded <strong>rubygems-2.4.1.zip</strong> does not contain any exe file, through which I can install it. I'm a beginner. Please help me.</p>