title: How to uninstall Qt5 commercial license
body: <p>I got quite desperate on this, because I cannot install the open source Qt5 after I installed commercial Qt5 on my laptop. </p>
  
  <p>This issue happened like this: My first trial of install Qt5, I chose the commercial license. Then when I tried to install PyQt5, it said my Qt5 license is commercial, not compatible with PyQt5 license. So naturally, as a open source lover, I uninstalled the Qt5. And reinstalled an open source version. But, no matter how many times I tried, PyQt5 says my Qt5 is still commercial license.</p>
  
  <p>Dose anyone encounter the same issue here? And how did you solve it?
  (I guess my last shot would be install a VM, but I sincerely hope I don't need to do that).</p>
  
  <p><strong>Updates:</strong> (July 28, 2015)</p>
  
  <p>The issues turns out to be PyQt5 is not compatible with the newest Qt 5.5.0 at the moment. Choose a older version of Qt.</p>