title: Failed to build gem native extension - extconf.rb not found
body: <p>When trying to install</p>
  
  <pre><code>'bcrypt-ruby', :lib =&gt; 'bcrypt'
  </code></pre>
  
  <p>and </p>
  
  <pre><code>'hpricot'
  </code></pre>
  
  <p>I get this in both cases (Using Windows XP)</p>
  
  <pre><code>C:/Ruby/bin/ruby.exe: No such file or directory -- extconf.rb (LoadError)
  </code></pre>
  
  <p>I installed from here <a href="http://rubyinstaller.org/downloads/" rel="nofollow noreferrer">http://rubyinstaller.org/downloads/</a> Rb 1.8.6, including the devkit</p>
  
  <p>any hints?, thanks</p>