Its pretty good, the ATI is your only downfall, but the geforce your getting is just a bit better.., the games you want to play on it will do fine, only thing is with vista, 4 gigs are recommended for a gaming pc, but all non DX 10 based games will run perfect, no lag etc etc, but dont try the newer dx9 (Bioshock, Crysis, Unreal3, QuakeWars) or you will get a horrid, painfull, very horrid, very paining feeling within your gut as a your fps will sink horribly low, well unless you turn every setting to very LOW ....
but for the second gen games itle do good...

Cheers

Thats a nice rig, quad cpu is nice.

I did not know ATI made a 128 meg version of the 2400.. I remember them only making 256 megs and 512 meg versions..

It will run all games you want to play, not all on high though.

If you have a quad core cpu you might as well go for the best..

From ATI... I am getting this card instead of the 8800 gts.. (whomps it)
Newegg.com - DIAMOND 2900XT1GPE Radeon HD 2900XT 1GB 512-bit GDDR4 PCI Express x16 HDCP Ready CrossFire Supported Video Card - Retail

Or the 8800 gts
Newegg.com - EVGA 640-P2-N821-AR GeForce 8800GTS 640MB 320-bit GDDR3 PCI Express x16 HDCP Ready SLI Supported Video Card - Retail