try these options in order to see if it solves your problem
1. turn all your settings to low and see if that fixes the problem. then try running the game
(also make sure AA is off and all that eye candy crap in advanced settings)
2. if problem is still there, try running l4d (same can be done with css) with dx 8.
this can be done by right clicking on Left 4 Dead and clicking properties. then go to set launch options and paste this "-dxlevel 81" (without quotations) in there. try running the game again
3. if it still isnt working, make sure your card isnt overheating. there are programs out there that will show the temps inside your laptop. (typically you want your temps to be at least below 60 degress celsius). if overheating is the problem, you will need a better way of cooling the laptop down, either by taking more breaks to give it a rest or by buying a laptop cooler station thinggy)
4. if temp isnt the problem, ctrl+alt+del and look into your processes and services, see if there is anything out of wack in there.
5. it is possible that you picked up a virus somewhere and it is crippling your laptop. run a scan with your anti-virus. if you dont have an anti-virus (which is pretty dumb), download avg free.
6. as a second to last resort, uninstall and reinstall l4d and css.
7. and as a last resort, reformat your laptop. save all your important files to an external drive and reformat your laptop.
get back to me on this and tell me if any of this works.
