I don't know the answer but i have 7 and in 3 weeks time microsoft will no longer support it,you have to move to windows 10 as the 7 can't be protected properly
i'm being pushed to buy a new computer but i'm going to try it on my old one first,back the 7 up before you download 10
Have a look at Computer Active magazine. There's an article on using Windows 7 safely