WEI score randomly jumped up?

I am aware that the Windows Experience Index score means nothing, but I was just wondering what would cause a random jump up like this.

My computer shows up as this now:



Before it was the same but the graphics scores were both 7.8 instead of 7.9.

Also, I think its retarded that the computer is being judged by its HDD in terms of score. Me and most of my friends have good computers with basic HDD's, so we get low scores. Very annoying.