the 3200 is not really a card but rather a chip integrated into your motherboard, my guess is you should be ok at medium settings
use this site to see what games your PC can handlehttp://www.yougamers.com/gameometer/10087/
That website that you posted is actually for regular Call of Duty 2, not Modern Warfare 2 (mw2 is more like Call of Duty 6).
I prefer this website
to check for my games (mostly because it looks nicer).
Either one should work, they do basically the exact same thing.