Windows 7 was released on July 22, 2009. Ended Support on January 14, 2020. 10 Years of support...Oct 2025 end of support.
Windows 10 was released on July 29, 2015. Ending Support on October 14, 2025. 10 Years of support...
This might imply that Microsoft will support Windows 11 thru 2031?!? Seems like a very very long time to me.
This doesn't even take into account how long Microsoft had to support IE7 after they made so many under-the-hood changes, forcing a lot of bank sites and whatnot to either comply or tell you how to enable compatibility mode. I think that's why MSFT created compatibility mode to begin with...