Mozilla has extended support for Firefox on older Windows operating systems, with the new deadline for Firefox Old ESR set to August 19, 2025. Official support for Firefox on Windows 7, 8, and 8.1 will continue until September 2025, with a reassessment of this timeline planned for August. The extended support applies to Firefox 115 (Old ESR) and Firefox 128 (ESR), which will be deprecated on September 16, 2025. After this date, users must upgrade to a newer version of Windows and transition to Firefox 140 ESR to continue using the browser.