Error executing script, failure to load DLL

I am trying to apply one of my first applications in Qt5 with Python 3.5.2:

import sys
from PyQt5 import QtWidgets

def window():
    app = QtWidgets.QApplication(sys.argv)
    w = QtWidgets.Qwidget()
    w.show()
    sys.exit(app.exec_())

window()

But it generates the following error:

  

from PyQt5.QtWidgets import QApplication, QWidget
  ImportError: DLL load failed: The specified process was not found