I have a working Python 2.6 install and just installed the PyQt4 built for Python 2.6 (available at http://www.riverbankcomputing.co.uk/software/pyqt/download). When I try t
Download the program from http://www.dependencywalker.com to see if there was missing dll.
You need to point the program to the QtGui.pyd file from PyQt.
My case was using MSYS2's mingw-w64-x86_64-python3-pyqt4, it needed libpython3.5m.dll while pacman was already at python3.6