title: Changing QT_PLUGIN_PATH in environment variables causes programs to fail
body: <p>I am using anaconda 3 and when I turn python scripts to .exe using pyinstaller they failed to open and I got an error message that said,</p>
  
  <p><strong>Application can't start because could not find or load Qt platform plugin "windows" in " "</strong></p>
  
  <p>I looked on stack overflow and found a solution for it <a href="https://stackoverflow.com/questions/41994485/error-could-not-find-or-load-the-qt-platform-plugin-windows-while-using-matplo">here</a>, and it solved my problem. However, now when I download other programs from the internet and try to open them they display the same error,</p>
  
  <p><strong>Application can't start because could not find or load Qt platform plugin "windows" in " "</strong></p>
  
  <p>I have delete the QT_PLUGIN_PATH from the environment variables in order to make the program that I installed work, but when I do that my .exe fails to open and I have to add the QT_PLUGIN_PATH again to make the .exe work.</p>
  
  <p>Is there a way to make both my .exe and installed programs work without having to add and delete the QT_PLUGIN_PATH from the environment variables every time?</p>
  
  <p>In environment variables I have,</p>
  
  <p><strong>QT_PLUGIN_PATH="C:\Users\username\AppData\Local\Continuum\anaconda3\Library\plugins"</strong></p>