u can run most of the game u find but you may experience a very low framerates even the game graphical settings are set to Low .
if i were u , i'll get a
AMD X2 3600+ / 3800+ and ( make sure its socket AM2 , why ? 939 procs
already stop production its lucky if u can find one )

any mobo that supports either SLi or crossfire

2 gigs of rams if possible , even BF2 runs slower with 1gb compare to 2gb
another reason for choosing 2gb coz sooner or later u will need it , why not getting it now .

VGA , if you want a mid range vga card : ati 1650 series or 7600gt