While using the motion-based multiple object traking script the video player apears but doesnt run, just says "processing".

While using the motion-based multiple object traking script the video player apears but doesnt run, just says "processing". Its been more than an hour and it doesnt do anything in any of the two video sceens that appeared. I am using a video in mp4 format of 1 min duration of cars on a street. Computer is a new Windows HP OMEN.