How to write automated test in python for windows application?

I have to write code that tests windows antivirus application, which needs to test if the application blocks usb dive, scans it and cleans infected files, and unblocks. I know how to write code but I don't have any idea how to track another application's tasks. Can anyone give an advice where to start, and how to write this code? Maybe, someone can suggest a helpful tutorial how to write deployment test in python. Thanks!