Why does norton utility still say low system health after running all the performance and privacy scans

I have run norton's utilities 16 on my two computers since November 2015, today October 1 2017 both computers running windows 7 pro, show low system health,  I ran 1-click optimization and all the performance and privacy scans and it still shows low system health.

it shows the same three things no matter what I do it shows "clean registry" "clear document history" and "clear run history".

I would be greatfull for any help.