I have just recently started using python and it worked for me last night. for some strange reason when I logged on to windows, some of the icons changed to the unknown icon and python was one of them. I'm not sure what happened or how it happened but I re-installed python and when i right click a .py file it says edit in idle. when i select that is gives me a screen where i have to choose from a list of programs to launch it with. i have done this process many times and i get the same outcome.

Thank You!