Installer states: Sorry Firefox can't be installed. this version requires MS Windows 7 or newer. My PC is running MS Win 7. Firefox was on my machine until 2/18

I have been running Firefox on my PC with no issues since Mar 2018. Then last week i started to get this line of info at the top of the screen when when I started Firefox - search.hquickmapsanddirections.com/?uc=201... etc. [ See attached file ] Since i was unable to get back to the Firefox window i was used to for almost a year, I decided to UNINSTALL Firefox. i then downloaded Firefox installer but could not install it again, getting an Installer window that reads, "Sorry, Firefox can't be installed. This version of Firefox requires MS Windows 7 or newer. I'm running MS W7. Thank you, Jules Bosch jbosch1@verizon.net