title: FileNotFoundError: [WinError 2] The system can't find the specified file
body: <p>I'm currently learning how to use the module <code>subprocess</code> and I just started with my new book. Instantly, I got an error message which I don't understand.</p>
  <pre><code>Traceback (most recent call last):
    File &quot;D:/me/Python/subprocess.py&quot;, line 3, in &lt;module&gt;
      proc = subprocess.Popen(['echo', 'Hello there'], stdout=subprocess.PIPE)
    File &quot;C:\Python34\lib\subprocess.py&quot;, line 859, in __init__
      restore_signals, start_new_session)
    File &quot;C:\Python34\lib\subprocess.py&quot;, line 1112, in _execute_child
      startupinfo)
  FileNotFoundError: [WinError 2] The system can't find the specified file
  </code></pre>
  <p>I couldn't figure out <strong>what is wrong here</strong>:</p>
  <pre><code>import subprocess
  
  proc = subprocess.Popen(['echo', 'Hello there'], stdout=subprocess.PIPE)
  out, err = proc.communicate()
  print(out.decode('utf-8'))
  </code></pre>
  <p>In the book they said this code should print 'Hello there' on the screen but for some reason, it doesn't.</p>
  <p>What is wrong here? I'm currently using python 3.4.3, if that helps you.</p>