skipping would probably mean that your system is having a hard time keeping up. it could also be the fact that you don't have enough RAM and it has to keep swapping back and forth to the pagefile.
its always good to use the best player possible, but you might also want to make sure you have enough system resources. if you don't want to buy more RAM, then trying closing as much stuff as possible before playing the video (especially stuff that is running in the background unecessarily)