ok, so when I launch L4D demo, it gives me a message about how my video driver is not up to date. I am running on a laptop, so I go to HP's site (cant download straight from nvidia). I download the latest driver update, install it, and restart my comp. still gives me the message. it says my current driver is #blablablawhatever, but that is the newest one on HP's site. it wouldn't be a big deal, because I can just hit 'continue anyway'. problem is, the film grain effect isnt showing up (yes I changed it in options). I think it's a cool part of the visuals, and would like to play it with it on, but I can't. any help?