Re: Trying to upgrade this for gaming.
You could always up the GFX card, but you would need to replace the power supply to feed it. You could possibly add some more RAM, but anything over 2 gigs wouldn't give you a real return. Since it is a pre-built, you can't really overclock it, so extra CPU cooling would be sort of pointless. The link didn't state the socket, but I am guessing either 478 or an early 775... either way you are pretty well stuck for upgrading the CPU.
You're next big step will have to be a new system. You could scavenge parts from your current system, or you could build new and have the old one as a spare.
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