Sudden FPS drop during games

Hello.

Another FPS drop problem here. Basically, whenever I play video games (LoL, TF2, Skyrim), there seems to be random FPS drops corresponding to spike in CPU usage. I can usually get about 50-60 FPS in games using moderate settings, but during the lag, FPS drops to 1-5 FPS.

I used perfmon.exe in Windows 7, and I found that the range of time that I experience FPS drop corresponded to spike in CPU usage (task manager was useless). Then I looked into whether my GPU is overheating during the times, which I found to be not true (temperature only increased by few degrees from normal use temp). The memory usage is definitely not the issue here since I recently upgraded to 8GB of ram (both 4GB sticks work fine as tested by memtest84).

Now I know that some program is causing the increase in CPU usage, but I dont know what is causing it. I thought it was firefox with pandora on, but closing firefox did not solve the problem. Could it be some sort of virus/malware? I know there are no anti-virus scans, defrag, etc going on during the lags.

Here are some specs of my laptop:
Intel i7 Q720
8GB RAM
ATI mobility radeon HD 5730
Windows 7 x64 SP1
 
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