Well unless you want to rebuild, or buy a whole new computer I would at the very least buy a new GPU. That was not a great card when it came out 3-4 years ago and you could upgrade it quite a bit for a couple hundred. Other than that your CPU is kinda dated aswell.

I don't personally believe that the story, or the jedi code was the biggest problem with episode 1-3. For me the story and action scenes where good enough to warrant paying the ten to fifteen dollars for a movie ticket, what did it in for me was the bad acting. Don't get me wrong it was not all bad but the kid who played a young anakin was extremely flat. I hate to say anything bad about someone so young but there have been plenty of child actors with more emotion and better deliveries. With a title like star wars you would think it would have a budget that never ends, yet it seems like the casting could of been much better in some areas.