I'm pretty sure that computer has a video card already but the question remains what video card is in there.
go to your control panel>device manager>expand 'Display Adapters
and it should be listed right there.
but in any case you might also ask for help in the SH IV forum since there's a lot more activity going on and a lot more knowledge is there regarding issues with the game.
hope you get it sorted
HunterICX