But does your "Abour WIndows" show you on build 10582?
The source of my earlier post is from an article where it seems to be that Microsoft is taking the hard line of forcing the windows 10 update on those with earlier (legal) windows versions. Including tactics like downloading it into a hidden directory on your C drive without permission and sneaking in the install as a part of the usual innocent updates. As I mentioned there are ways around it and if you are using a corporate or cracked Win 7/8/8.1 you'll be left alone.