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It's not XP. Looks like 7 with the last decent theme that's ever came from them.

Nope, that is definitely XP, past Vista the Windows 2000 like theming was removed.

It wasn't. Classic Theme was available on Windows 7 and Windows 8. https://www.google.com/search?q=windows+7+classic+theme

the windows version in the demo video is windows 7 ultimate