Biggest bottleneck for my gaming pc?

I recently purchased a computer for gaming and after playing for a month on WoW with it I was slightly disappointed in it's performance compared to my old computer. I get 20ish fps and minor stuttering in high population areas and raid situations with settings on high. I paid a couple hundred less for my computer then I had originally expected so I'm looking to put that extra money back into the computer and need some advice on what to upgrade. Specs are as follows:

Windows Vista Home Premium 32 bit
Q6600 2.4GHz
Intel G33 Express Chipset
Corsair XMS2 Xtreme Performance 4GB PC2-6400 DDR2
320GB SATA 7200RPM
ASUS 4850HD
Antec True Power Trio 650W PSU

My monitor runs at 1650x1050. Any help you can give me would be greatly appreciated.

On that rig you should NOT be getting 20is fps in WoW....you should be pulling five or six times that framerate at least! Make absolutely sure you download and install the latest ati/amd drivers for your video card.

WOW has mostly had poor performance in vista compared to XP

Never played WOW, but you are using an integrated Intel GMA 3000 (??) video solution. Integrated video is general considered not to be good enough for gaming.

My guess is that your previous computer had an add-in ATI or nVidia video card.

K first ... if you have an integrated video card on your board disable it (in the BIOS)... its even worst if you noobilly connected your screen to the VGA plug of your motherboard lol ... could happen ... if your sreen is in fact connected to the VGA (Via adapter) or better DVI connector of your video card, that the PCI Express Bus is prioritized in the BIOS, the Integrated Video Chipset is off and all of your drivers are up to date ... well i can only assume that you have a crappy internet connexion ... cuz your have a hell of a good computer there ! the one ill build soon is similar to that.. Well kinda boosted with steroids ... hehe

Q9450 FSB 1333 (338$) with a ASUS Triton 79 Cooler (65$)
Asus P5E3-DX IX38 Wi-FI (320$)
4 GB DDR3 1333 Kingston (244$)
Sapphire RADEON HD4870 (307$)
1TB Sata II (150$)
Pioneer Blue Ray Reader (153$)
PSU NSPIRE 850W 4XPCIE (142$)
Windows Vista Ultimate 64 bit (212$)
All in an ANTEC 300 Case (51$)

BENQ G2400WD 1920X1200 (380$)

With all applicables fees .. 2800$

I think i have quite a good bargain ! And a freakin machine
Cant wait to get it

You were right the first time. He has an HD 4850.

Also, OP, with this rig there is absolutely nothing that you need to upgrade.
There is a problem when you're only getting 20 FPS in WoW with a rig like this, but it most certainly is not due to weak or lacking hardware.

lol...sorry guys, i guess i need to get some sleep!

where did op go? anyway, do you have this problem in other games, or is it just WoW?

^^ I think he means VAT ( at arounf 14.5% ) as the applicable fees

Not a bad machine mate - should be a good gaming rig for sure.

@ the OP --> Unless you have some hectic spyware running ( check your Task Manager CPU level in the Processes Tab. Should be 99% System Idle Process before you start playing WOW. ) you def shouldnt be getting such bad FPS. Unless you are totally noob even drivers will only cost you like 10FPS - driver issues will mostly cause massive jerking, black screens, CTD's or graphic artifacts in the game.

So im going to agree with everyone else here. You need to disable your Integrated Piece Of Crap in bios. But - like the poster above said. Check which socket you plugged the screen cable into