Did you recently uninstall an application that was using Visual C+ runtime components? 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 Download the latest vc_redist.x64 and vc_redist.x86 files. *https://aka.ms/vs/17/release/vc_redist.x64.exe *https://aka.ms/vs/17/release/vc_redist.x86.exe You need to reboot the computer. <hr> *https://support.mozilla.org/en-US/kb/troubleshoot-and-diagnose-firefox-problems