I have an active Windows 10 key on my system with Windows 10 installed and I keep getting prompt on startup to upgrade to Windows 11.
I have ignored these upgrades since I am not sure if I decided to upgrade to Windows 11, will my Windows 10 key no longer work for Windows 10 installation and only work for Windows 11 installations going forward once I upgrade?
There literally isn’t a difference between a license key for Windows 10 and Windows 11 (maybe things are different in Enterprise licensing, but definitely not for Windows Home and Pro) If Windows 10 is activated on your PC, you can install either without issue.