Usage share of operating systems computer's installed base statistics, and actual (web) use needs not follow installed base. Also, Microsoft includes tablets (but StatCounter may also for Windows, while it wouldn't for e.g. Android). Video game store Steam publishes a monthly "Hardware & Software Survey", with the statistics below: By Q1 2018, mobile operating systems that can be found on smartphones, include Google's dominant Android (and variants) and Apple's iOS, with both combined at almost 100% market share. According to research by InsightPortal, there is a clear correlation between the GDP per capita of a country and that country's respective smartphone OS market share, Showing
Usage share of operating systems developer survey provides no detail about particular versions of Windows. The desktop operating system share among those identifying as Professional Developers was: In June 2016, Microsoft claimed Windows 10 had half the market share, then in the US (and UK), of all Windows installations (only), as quoted by BetaNews: As of February 2017, Microsoft's trend page has Windows 10 (for global data) at 47% (for "PC and tablet: All users"), more than any other Windows version, and at 56% (for "PC and tablet: Gamers"). Note, while data seems contradictory and limited, all data is; Microsoft may have good access to