L4D2 lags

it just lags. when ever i play single player the game tends to have some pretty bad lagging issues, slow animation, and weird firing. i deleted some stuff and the game gotten 85% better. however when i play split screen the lag comes back. how can i fix this?

you lag. this game is great

well my cuz says that sometimes a bigger TV tends to lag just a bit, even if your're not playing live. he plays L4d on his small TV(about 20") and theres no lag at all. i own a HD TV thats 50".(720P) should i sell the game instead?

Whats the condition of the disc like as i've not had such a problem with single player or split-screen. I've had some lag online, but thats usually when playing people across the atlantic.Raiko101

the condition is flawless. not a single scratch at all.

ok thanks and i will try.