My wife has a Dell XPS 435T/9000. It has an I7920, 2.67Ghz with 8Gb memory, seagate 750G hard drive and a Radeon HD5450. I am trying to improve her gaming performance, specifically world of warcraft. I think a new video card is need because there is some lag when the video settings are high. Would you agree or is there something else I should try to upgrade? What video card would be a good choice, looking to stay under $200.