Well I was on El Capitan and decided to upgrade. I got the copy of the Sierra MacOS to my pen drive from a Local Shop. I had perfectly upgraded and everything is fine. But when I I opened the App Store I saw download Button below the Sierra os. fe868eb619a16406e5082ff08ba92100.png I am now confused. If I download a software once in my Mac in App Store it won't show install button cause I already have it. Did I do correctly ? I tried to check update online. It said No update available on my os. Do you see DOWNLOAD button in the App Store after even installing the OS. or am alone and did some wrong?? Please answer and I am just confused. It might be so silly. Sorry but I am confused.