title: "RuntimeError: Make sure the Graphviz executables are on your system's path" after installing Graphviz 2.38
body: <p>I downloaded <code>Graphviz 2.38</code> MSI version and installed under folder <code>C:\Python34</code>, then I run <code>pip install Graphviz</code>, everything went well. In system's path I added <code>C:\Python34\bin</code>. When I tried to run a test script, in line <code>filename=dot.render(filename='test')</code>, I got a message</p>
  
  <pre><code> RuntimeError: failed to execute ['dot', '-Tpdf', '-O', 'test'], make sure the Graphviz executables are on your systems' path
  </code></pre>
  
  <p>I tried to put <code>"C:\Python34\bin\dot.exe"</code> in system's path, but it didn't work, and I even created a new environment variable <code>"GRAPHVIZ_DOT"</code> with value <code>"C:\Python34\bin\dot.exe"</code>, still not working. I tried to uninstall Graphviz and <code>pip uninstall graphviz</code>, then reinstall it and pip install again, but nothing works. </p>
  
  <p>The whole traceback message is:</p>
  
  <pre><code>Traceback (most recent call last):
    File "C:\Python34\lib\site-packages\graphviz\files.py", line 220, in render
      proc = subprocess.Popen(cmd, startupinfo=STARTUPINFO)
    File "C:\Python34\lib\subprocess.py", line 859, in __init__
      restore_signals, start_new_session)
    File "C:\Python34\lib\subprocess.py", line 1112, in _execute_child
      startupinfo)
  FileNotFoundError: [WinError 2] The system cannot find the file specified
  
  During handling of the above exception, another exception occurred:
  
  Traceback (most recent call last):
    File "C:\Users\Documents\Kissmetrics\curves and lines\eventNodes.py", line 56, in &lt;module&gt;
      filename=dot.render(filename='test')
    File "C:\Python34\lib\site-packages\graphviz\files.py", line 225, in render
      'are on your systems\' path' % cmd)
  RuntimeError: failed to execute ['dot', '-Tpdf', '-O', 'test'], make sure the Graphviz executables are on your systems' path
  </code></pre>
  
  <p>Does anybody have any experience with it?  </p>