If I'm not wrong, your CPU is a core 2 firstname.lastname@example.org. If that be the case, your CPU is good enough. What brand is your PSU? That can be a point of concern!
As for the GPU, the 9800GT has been a respectable card for quite a while. Though, for that price today, one can get a GTX460, which offers DirectX 11. Plus, it's newer tech. As gamerk316 said, it's started to show its age.
Nonetheless, at medium resolutions/ medium settings, that card will perform sweetly.