Sell or upgrade?

Hi,
I am having problem. what to do?

I have this system.

Dell XPS 410
Dual Core Intel Xeon Proc E5205
3 gig of ram running dual channel
250 gig hard drive
nvidia 7900 gs
samsung lcd 22"
Vista
400w

Any suggestions?

Depends on your wish how much you are willing to spend! Theres not a lot in it for most games with both CPUs running the same speed. Quad is slightly ahead. However you are likely to get a fair bit higher overclock out of a dual core so its not quite cut and dry. There are a few games that do benefit well from Quad cores though and I'm sure more are coming.
So I would hedge my bets with a good overclocking quad if I was buying now.

if u mount the intel supplied cooler over Dual Core Intel Xeon Proc E5205 ,its gonna be a too much loud , and too hot so ur computer is gonna turn to an oven while overclocking , ha by the way if there is intel mobo for u then forget Oc'ing , ur best bet a quad core over Asus gigayte board