Under this situation, you need help from MobiKin Assistant for iOS (Windows Version).
However, there are still so many limitations of iTunes, so that it is troublesome to use iTunes on PC.
In case of losing data if your iPhone is stolen or broken down accidentally, or you just want to share the movies on your iDevice with your friends in other ways, you need to back up your files on iPhone, iPad, or iPod to iTunes time to time.