ricardois :
first of all you don't have directx 11, since this is a graphics card feature and 9400 gt don't have it.
i think your video card cannot play farcry on very high, it is weak... you should upgrade it, go for a 9800gt or a gts250 minimum, this will alow you to go for very high i believe.
Also add some more ram e go for windows 7 x64.
Erm, the gts 250 is a terrible card which also does not support DX11, please do a little research on what your recommending.
I would go as far as to say in reality you should upgrade the whole of your pc if your wanting to play games on very high settings.
The only part which may be of us is what I would guess is an i3 proccessor, which if you really wanted you could probably get high settings with.
Your memory is a fair bit low, ideally atleast 4 gig.
I would advise you make a post requesting a build using the new build template if you REALLY want to go at it for high end graphics.
at a push however you could get away with getting a 6**** version graphics card and a couple of gigs more ram, from there you probably could run a few games on high.