I need to stop your updates because you have now blocked all of my photo files

You need to go to Tools -> Settings -> General Tab.

Then, scroll down to the Firefox Updates section and make sure Check for updates but let you choose to install them is selected and Not Automatically install updates (recommended).

I've had that selected forever and it's never automatically updated on me.

I think one of the biggest problems is that they send out updates for Windows 11, and I am using only Windows 10 on this specific computer. So, they have been covering all my photo files since they started downloads for Windows 11.

They as in Mozilla?

There are no Firefox versions just for Windows 11 as Firefox versions since 116.0 to current has been for both Windows 10 and 11. https://www.firefox.com/firefox/147.0.1/system-requirements/

Also Windows 11 itself it basically based on same NT 10.0 as Windows 10 anyways. https://en.wikipedia.org/wiki/Windows_NT#Releases

You were given replies in your previous two threads https://support.mozilla.org/en-US/questions/1535184 and https://support.mozilla.org/en-US/questions/1533962

A link was posted by jscher2000 and is for Windows 10 if you clicked on Windows 10 in https://support.microsoft.com/en-us/windows/common-file-name-extensions-in-windows-da4a4430-8e76-89c5-59f7-1cdbbc75cb01

And if you still miss that then click on https://support.microsoft.com/en-us/windows/common-file-name-extensions-in-windows-da4a4430-8e76-89c5-59f7-1cdbbc75cb01#id0ebf=windows_10