I downloaded the recommended version in both cases. My desktop is a dual core, mabye it missed something. Wait, I remember something about this. When the first program was finished, there was some message relating to freeing up the core. I don't know, on my other OS (Ultimate), I'll pay closer attention as to what's offered to me. I just downloaded the top one from the list, being that they recommended it, based upon information obtained from my browser. Next time, I'll use IE to download with, there are fewer security add ons, and that may have played a hand in the recommendation.