Few things I found I had to do to make this work with Windows 7 64bit.
I place the file in the same directory as the .ini files and the main software.
The post processing has to have the full location linked, if you right click on the file just copy the "Location" entry and put this directly behind it /clean_gcode.py "<FILE>"
Make sure the file opens with python, I have Windows wanting to open it with Wordpad for some reason. lol
Hope that helps you out.