Lag when I start shooting

My laptop will run CF fine until I start CQC, or when I kill someone. When either of these two things happen, the game will lag, often causing me to die. For example, I kill someone from far with a headshot. The game will then lag for about 1/4 of a second, then the kill mark will pop up. In CQC, the game will lag the second someone from the other team comes into view and I start shooting.
I have an Acer laptop:

Here are what i can tell of the specs:
-Duo Processor (160 GHz, 533 MHz FSB, 2Mb L2 cache)
-Intel Graphics accelerator 950
-100 Gb hardrive (I don't think this matters)
-1GB DDR2
-Windows XP (Media Center Edition)

I have no idea where to begin to fix this problem, so I was wondering if you guys could help me. Thanks

Oh, and my internet is more than capable of keeping up, as my pings are usually in the mid 30's to low 20's.

Thanks