It's ok. What do you mean by run any game? Do you mean run it on high settings, low settings or what? Because that could run Crysis with a med/high cross, bias towards the high, 4 gigs of ram is too much for XP Pro (I'm pretty sure) so I would get the Win7 RC or Vista pro.
A 9600GT card or better is all you need for the GPU.
Your computer now could run any game out there now, just not on the highest setting.