when you upgrade from windows 7 to windows 10 does it really upgrade to win 10 or
does it upgrade win 7 to win 8.1 ?

Reason why I ask this is because I just use BelarcAdvisor Belarc Advisor - Free Personal PC Audit, for software, hardware and security configuration information on your computer. Software license management, IT asset management, cyber security audits, and more.
and it displayed all my specs but shows Windows 8.1 Professional after I did the windows 10 upgrade.

Now when I use Magical Jelly Bean Keyfinder Magical Jelly Bean that shows
that I have Windows 10 Pro Windows 10 Pro Product Part No.: [TH]X19-9 Installed from
'Full Packaged Product' media.

which one these is more accurate can anyone explain..