Have you tried Firefox in Safe Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#w_how-to-start-firefox-in-4troubleshoot-modesf5safe-modesf Also try using a different Windows account to see if you have the same issues. What security software are you running?

You can check for issues caused by a corrupted or incomplete Visual C++ installation that is missing runtime components (Redistributable Packages) required by Firefox, especially VCRUNTIME140_1.dll. See "Visual Studio 2015, 2017, 2019, and 2022": *https://docs.microsoft.com/en-US/cpp/windows/latest-supported-vc-redist *https://aka.ms/vs/17/release/vc_redist.x64.exe *https://aka.ms/vs/17/release/vc_redist.x86.exe You may also have to install the Visual Studio 2013 Redistributable Package. You need to reboot the computer. ---- It is possible that your firewall or other security software blocks or restricts Firefox without informing you, possibly after detecting changes (update) to the Firefox application. Remove all rules for Firefox from the permissions list in the firewall and let your firewall ask again for permission to get full, unrestricted, access for Firefox and the plugin-container process and the updater process. See: *https://support.mozilla.org/en-US/kb/server-not-found-connection-problem *https://support.mozilla.org/en-US/kb/Firewalls *https://support.mozilla.org/en-US/kb/fix-problems-connecting-websites-after-updating