What do you mean remove a 2GB fail ? (Do you mean a failed RAM stick?)
You can reduce lag but lowering the settings like taking off "glow",
lowering texture quality
and stuff like that.
But I think the jump thing (when switching windows) is nothing to do with lag because
it happens even on fast computers.
Try out different settings and see how fast you can get it.
What's your FF name going to be?
"SkyFallen" ?