I think you should instead download firefox from firefox site and use that one just incase there is issue with Microsoft site.

https://archive.mozilla.org/pub/firefox/releases/ --- this is a archive site and has old/new release and different language version ---

https://www.mozilla.org/en-US/firefox/all/

edit: fixed links

Thanks. I was in S mode and didn't know it. I thought S mode meant safe mode. I exited out of S mode and now am making progress!

I can't figure out how to install Firefox on Windows 11. Their link gets me to APPS in Setting but from there I'm lost. I can't find in APPS where to allow for apps from third parties. I think MS does this on purpose.

Where are you getting Firefox from?

You can either get Firefox from https://www.mozilla.org/firefox/all/#product-desktop-release or you can get it from the Microsoft store.

https://support.mozilla.org/en-US/kb/how-install-firefox-windows

Thanks. I was in S mode and didn't know it. I thought S mode meant safe mode. I exited out of S mode and now am making progress!

https://support.microsoft.com/en-us/windows/switching-out-of-s-mode-in-windows-4f56d9be-99ec-6983-119f-031bfb28a307

Windows 11 in S mode is designed for security and performance, exclusively running apps from the Microsoft Store. If you want to install an app that isn't available in the Microsoft Store, you'll need to switch out of S mode.