How well would my PC run games?

How well would this PC run games like COD4,COD5,Medal of honor:airbourne,crysis and f.e.a.r.?(I don't want to max crysis or w/e,medium settings would do).

P4 3.2GHz,1GB of ram and a 512mb 3850.(Resolution is 800x600 or 1024x768).And what if I upgraded the ram to 2gb's?Thanks in advance.

that card will do very good at high settings at those low resolutions and adding a extar gig would help improve ur performance.

edit that p4 will hold u back so u would be good upgrading ur processor to a dual core if u could. 

I might get an e5200 for like x-mas and also upgrade to 2gb of ram,how would I do then?darx55