How well (SHOULD) my computer play WoW?

I'm not very good with computers, but I'll try and give the best information I can.

Video Card: NVIDIA GeForce 9100

Total Available Graphics Memory: 1919MB

Dedicated Video Memory: 256MB

Shared System Memory: 1663MB

(Approx) total memory: 1905MB

Current Display mode: 1024 x 768 (32bit) (75Hz)

Processor: AMD Athlon(TM) 64 X2 Dual Core Processor 5400+ (2 CPUs) ~2.8GHZ

Memory: 3838MB

Ram: 4GB

Directx: DirectX 10

I'm not sure if this is all you need, but..if you can help me, and tell me what I need to improve, and how..It'd be well appreciated.