, also known as the November Update , was a major feature update released by Microsoft in November 2015. It marked a shift from Windows as a static OS to a "Windows as a Service" model, introducing features like a revised Start menu, Cortana improvements, and Edge browser enhancements.
If you previously activated 1511 with a key and need to reinstall, extract the key from your current installation using a script or tool. windows 10 version 1511 product key