The short version:

The short version:

* The mainstream support for Windows 7 (Service Pack 1) ended on January 13, 2015, and the extended support ends on January 14, 2020.
* The mainstream support for Windows 8.1 ends on January 9, 2018, and its extended support will end on January 10, 2023.
* The mainstream support for Windows 10 ends on October 13, 2020, and its extended support will end on October 14, 2025.

But you'll need to read the article to figure out what the difference between mainstream and extended support is.
https://www.guidingtech.com/67821/microsoft-support-end-windows-7-8-10/