Answer: 6.2

The box might say Windows 8, the marketing materials might say Windows 8, and you might say “I really don’t like this tiled user interface in Windows 8, where’s the Start Menu?” but if you ask the operating system itself which version it is, you’ll get a much different answer. Windows 8 will tell you, if you call up the Version API helper function, that it is in fact Windows 6.2.

This curious discrepancy between what the marketing name is and what the actual version of the OS is stems entirely from a divorce between how the releases of Windows have been marketed since the Windows Vista to Windows 7 transition and how they are numbered internally. When Windows 7 came out, it was the 7th major desktop release of the popular operating system (there was a little fuzzy math involved as they certainly didn’t count releases like Windows ME). Internally, however, Windows is still numbered based on how many versions removed from the original Windows NT kernel it is. So while we called that release Windows 7, the actual Windows version was only 6.1 (a single step up from Window Vista’s 6.0 designation).

In turn, Windows 8 is only Windows 6.2 (and with the release of Windows 8.1, now Windows 6.3). Although this contrast between the marketing name and the internal name might seem silly to an outside observer, there’s a practical consideration (and a rather important one at that). In terms of program compatibility and system functions, the operating system and the programs that run on it don’t care about marketing terms, they care about consistency. The next major release of Windows could be called Windows Ultra 2600 Sparkle Town and it would still have a standardized internal version number like Windows 6.4.