Hi @fritfrut, thanks for the helpful comment. I've tried following your steps and I now have both pycairo-1.17.1-py3.6-win-amd64.egg and PyGObject-3.28.3-py3.6-win-amd64.egg. I've tried easy_install-ing these egg's and now python can import gi but gi.gi.require_version("Gtk", "3.0") fails with ValueError: Namespace Gtk not available Also, I can run gtk_demo.exe fine from GTK's build bin directory. Does this ring a bell? Can you give a bit more details on how you set it up once you had the libraries...