From my mac OS 10.8.5 I downloaded OS Sierra from app store. It said it was downloaded and the icon was in my apps folder. I clicked it, agreed, gave my password, but it wouldn't install.
Per advice from Mac Support, I dragged the download to trash, and did a new download (took 22 hours). However, that one will not install either. I tried restarts, holding keys down and everything suggested, but still nothing. It's a mac mini 2013, OS 10.8.5. I gave the serial numbers to Mac Support over the phone and they said it should work.
Why will it not install?!