I believe the the latest version is 4.0.5.6. I f you go the top of this page, under support, you will get a drop-down where you can choose support by product, pick GTP4. Hopefully this will help, and there is something I remember about running as Administrator first time, then holding shift while you open, I'm not sure. Hopefully someone can chime in and clarify, and if need be call support, good luck!