Looking to upgrade Dell Desktop

Well guys,I'm in bit of a fix here,I want to play games like GTA 4 and Crysis,but i've got a pretty pathetic rig:
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Dell Inspiron 530s (slim model)

Seagate 250GB HDD

Intel Dual core E2200 @2.2 Ghz 1 MB cache

Gma 3100 graphics chipset(inbuilt crap)

3GB RAM DDR2(I have four slots.2x512mb Ram;1x2GB Ram)

250W PSU
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Now this is what I'm gonna upgrade to:

Intel Core 2 duo E8400 @3.0 Ghz 6 MB cache

ATI Radeon 4770 GDDR5 512MB (low-profile)

500W PSU

*everything else same

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So the question is here:

Is this good enough to play GTA 4/Crysis on high quality?

Is the E8400 Better than the Q6600? (And there is NO way i'm overclocking,coz I can't upgrade my stock fan coz it's a slim case )

If the Q6600 is better,can my mobo support it? (GTA 4 uses multi threading)

I think the graphic card is the best i can get,in a slim case.Do you agree?

Will anything bottleneck anything else?

Should i install more RAM? And go 64 bit vista? I already have XP 32bit,now.

And i heard that if i have 4 slots,2 with 512 each and one with 2GB,It will be better to get the last one as 2GB.If I add 4gb in the last slot,will performance downgrade?Is this fact true??

Thanks

-JD

Ok well sorry to say but most people here read through a post like this get a little chuckle and move on. Your power supply and the fact that this is a slim case make the odds that this upgrade is a good idea slim. The ram should be done in pairs and if you have more than three gigs yes go 64 bit Vista or you will only be able to access 3.25 gigs of it. I will say you might get this upgrade to work but your power supply will not last long as it will be doing everything it can just to idle... And that e8400 will get smokin hot in that slim case I had a e8500 and it warmed up the room a bit in an antec 900. I would poke around a bit on ebay or something for the 350w PSU they make for this model it will still be close but more doable.

T

Help a guy out people

You can get an antec 300 case for $49.99 shipped at frys.com which will take any standard atx power supply and all atx and micro atx boards.

Ok so I asked the dell guys and they said I can upgrade to a godd quality 500-600W PSU.
So will I be able to run a Q6600 on it? Will that be better than a E8400?

Well,I have the slim one, but there are some PSU's in the market that can fit easily.And will the E8400 perform good at games,while AVG,windows sidebar,and other normal apps are running?Can you tell me why it would be better than the quad?

Well the 530s is only gonna be alive till 2011,after that,I'm going for a XPS/M17X Laptop.

Do you think I should just get a better fan,and OC the E2200 @2.2 to 3.0 ?

Can't overclock it, no reason for a new fan.