My System:

Hi, I've been having a problem with my laptop recently, it's freezing for a second or two every few seconds, it's highly frustrating.
The CPU's only running at about 20%, memory used is at less than 50%, but the computer struggles...
I've tried a number of things, including:
1) system check
2) defragging
3) ran Symantec full scan
4) ran spybot SnD
5) closing unnecessary tasks/processes
6) checked CPU temp with Everest (59degC)
It's to the point where I can't watch a movie or listen to music, because it stops for a second constantly.

My specs are:

Acer Aspire 3356G
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AMD Athlon 64 x2 dualcore processor (2.1GHz, 1MB L2 cache)
4GB DDR2 Memory
320GB HDD

If more info is needed I'm happy to provide, sorry I'm a bit of a noob...