Belarc Advisor just doesn't support Windows 10 yet

Don't believe everything you read on the Internet.

Here's a screenshot of my Belarc Advisor report. Whoa, Windows 10 is really Windows "X" under the hood!

Not really.

I just modified NPBelv32.dll, which houses a matrix of operating system versions and strings for report generation purposes. I suspect when Belarc updates their agent, the Windows 9 artifact will disappear.