Whenever I try to load Minecraft, it gives me an "org.lwjgl.LWJGL Exception: Pixel format not accelerated"

I have Windows Vista Home Basic, used device manager to auto-update my ATI RADEON XPRESS 200 graphics driver, updated Java, and still can't figure this out. I have no idea how to work computers, is it possible I need a better graphics card? If so does anyone know any? Nothing fancy, just bare minimun. Thanks.