Believe it or not Windows 10 was released (general availability) on June 29, 2015, four years ago! As far as Operating Systems is concern, you can say it is now a pretty mature one.
Since its release there has been 8 different version releases (feature updates) and well over 130 different monthly cumulative patches (quality updates) across all versions.
About 39 Years ago Microsoft release Windows 1.0 – Bill Gates said at the time:
On November 20, 1985, two years after the initial announcement, Microsoft ships Windows 1.0. Now, rather than typing MS‑DOS commands, you just move a mouse to point and click your way through screens, or windows. It is unique software designed for the serious PC user.”Bill Gates Circa November 1985
Pretty amazing I you think about it!