Buying a gaming pc help!

I’m trying to build a gaming pc on dell. I thought about building one myself but decided against it. So my question is, will this pc I build be a strong gaming pc, what should i upgrade? Thanks

Components
-Intel ? Core?2 Duo Processor E6400 (2.13GHz, 1066 FSB)

-Genuine Windows Vista? Home Premium

-19 inch E197FP Analog Flat Panel

-2GB Dual Channel DDR2 SDRAM at 667MHz- 2DIMMs

-320GB Serial ATA Hard Drive (7200RPM) w/DataBurst Cache?

-16x DVD+/-RW Drive

-Intel? Graphics Media Accelerator X3000

-Integrated 7.1 Channel Audio