Well... this is what I'll do:
1. I will buy a new CPU heat sink
2. Play the same games, and see if the problem appears again.
3. If so, i will then continue testing my components
4. If i put a core2quad Q6600 @ 2.44 GHz or a core2Duo(probably 2.6-3.0), i will have to change my CPU heat sink anyway? -Am i correct.
So buying a better CPU heat sink isn't a mistake as i can see.
BTW can i ask for some advice about upgrading my pc?
1. as Solarstarshines mentioned, I should change my CPU MB and RAM.
2. I would like to stay on this board
3. Probably I am going to put 4 GB of new memory
4. I need a good GPU, not only for gaming. I am not a addicted to games... probably a 1GB card, but with a higher clock.
p.s. I have 18 years. My parents don't buy me these kind of things, neither do they give me money. I work in order to buy myself something that i want. That's why i have so old component's (in average, my pc is from 2008.) I'd really like to have a modern machine, and i know where to get all the components in like 3 days. Just don't have the cash...