Major lag in Left for Dead 2! Why?

When i go in either singleplayer offline mode, or online in a versus game, it’s completely unplayable. Im having major lags and i cant even get to the menu or do ANYTHING
I would say my computer is good enough for Left for dead 2, and i tryed setting it to the lowest settings, but no good.
This is my comp:
http://www.acer.co.uk/acer/productv.do?LanguageISOCtxParam=en&kcond61e.c2att101=59450&sp=page16e&ctx2.c2att1=17&link=ln438e&CountryISOCtxParam=UK&ctx1g.c2att92=122&ctx1.att21k=1&CRC=2288824938
I have Windows 7 32 bits, if thats any help.
Answer #1
Same thing is happening when i play counter strike source?
What can i do?
Answer #2
Help please ^^
Answer #3
The lowest settings, does this mean you turned anti aliasing off?
Answer #4
It’s because you only have a 2.0GHz dual core processor, and an integrated graphics card. No laptop will be able to efficiently be able to run new games unless you spend a good $1500-2000 on it. In order to play it with your current rig, you’re going to have to put settings to lowest, no anti-aliasing, blur, etc.
Answer #5
As said above.