title: os.startfile error: FileNotFoundError: [WinError 2] The system cannot find the file specified:
body: <p>I am running this in Spyder on windows 7. 
  I have tested this on multiple files, all of different types.</p>
  
  <pre><code>file = r'c/:folder/file.txt'
  os.startfile(file)
  </code></pre>
  
  <p>returns</p>
  
  <pre><code>FileNotFoundError: [WinError 2] The system cannot find the file specified: 'c:/folder/file.txt'
  </code></pre>
  
  <p>I have also tried to check if the filenames are correct, and os.path.isfile(file) returns True</p>