https://bugs.winehq.org/show_bug.cgi?id=54463
--- Comment #1 from Hans Leidekker hans@meelstraat.net --- This is because RtlGetVersion() reports the version taken from the CurrentVersion registry string and this string was changed to match recent Windows versions.
The solution is probably to look at CurrentMajorVersionNumber/CurrentMinorVersionNumber first, like we do in winecfg.