Graphic Card, CPU, RAM Combo Issue - Upgrade Help

1. Ouch, some people hate(with a passion) the Antec Earthwatt. I'm not sure a 430W PSU will handle our system. I mean, the GT alone is ~110W.
2. You do realize the cheapest GT will (supposedly) be $199 and the 512MB will (supposedly) be $249.
3. Yes, I would buy more ram. If you look for deal you can find 2GB kits(2x1GB) for around $55 after MIR.
4. I really don't know if the 4200 would justify being bought. I doubt there would be a huge performance boost. Is your current one a single core? What is your clock/GHz?
5. The basic minimum for games now-a-days is 2GB. It really does depend on what games you are playing, though. Buying the 8800GT will show an performance boost(In my opinion). I don't know if the performance boost would be with $65 for the CPU.

-Adam

Myself, I would look at building a new computer around an AM2 or 775 motherboard.
Even with a new cpu and 2 gigs of ram and that 8800GT, you may still be disappointed with the overall performance.
And what ever you do, don't jam that earthwatts psu it the box that you may build or currently have.
Start with a great power supply and build up from there.

I really like PCPower for psu's.

The great games today require lots of power from the computer components.

It will take some research, find what you want as to games, eye candy, and build from there.

Lots of info in the forums, here and elsewhere.

Have fun