https://www.theregister.co.uk/2018/02/05/statcounter_vs_netmarketshare_windows_10_market_share/

Web analytics outfit StatCounter last week trumpeted news that Windows 10’s market share overtook Windows 7’s for the first time in January 2017. But other ratings services didn’t find the same result.

StatCounter’s assessment of Windows version market share for January 2018 suggested that Windows 10 scored 42.78 per cent of Windows’ market share, as measured by worldwide internet. That compared to 41.86 per cent for Windows 7.