Help with an internal video card

[leoncour20]

My computer has a Radeon expresss 200 which is an internal video card and shares 256 megs of Ram. I have tried civilization 4 and the graphis are really choppy. The gamespy website said that my system passed all the tests, however I cannot play the game in this state. I was wondering if there was something I have to tweak or if I need to buy video card with its own memory. Thanks guys.