well, heres my two bit, seeing as you want to play with a controller, and from reading your post you have a crappy pc, just stick with DoD, or go back to your xbox. i mean, you'll get the updates on there. some day.
as for the controller on the pc, it can be done, not hard, just google it,
and i do have to agree with everyone else here, the best way to play a fos on the pc is with a mouse, unreal 99 comes to mind, but i bet you can still do well with a controller,
also
watch with the triple posting, i saw you do it twice so far.
also,
link.