Mozilla shut down support for Windows XP and Windows Vista, ending browser security updates for the outdated operating systems. Support for the two past-expiration-date OSes ended with Firefox ESR 52.9, which was released June 26. With Firefox’s pull-the-plug move, the only Top 5 browser still supporting the ancient OS is Opera. To keep receiving security updates, Firefox users on XP or Vista must upgrade to a newer operating system, such as Windows 7, Windows 10 or macOS 10.13.”]