This number includes only OEM and retail copies of Windows 8.x, volume licenses are excluded.
Still, in a PC market that's shrinking—and which started shrinking even before the release of Windows 8—200 million copies is perhaps not too shabby. PCs as a whole are not selling as fast as they were during Windows 7's heyday, and both Windows and Office are suffering as a result.Source: ARS Technica
As is almost always the case with these numbers, this is a sell-in figure rather than sell-through, which is to say that it represents the number of licenses sold to OEMs and retailers and not the number sold to actual end-users. It also doesn't account for people using downgrade rights (when available). These numbers never do.