Many seem to be forming opinions on Windows 10 without having seen it, based solely on their (often limited) experience with Windows 8. That’s just wrong.
The problem is that some third-party download sites (not all) actually add software to your download. It could be possible that Norton is correctly preventing you from downloading viruses.
The single biggest complaint about Windows 8 is the startlingly new tiled Start menu. Don’t like it? There’s an app for that.