Firefox just pulled the plug on Windows 7/8/8.1 — here’s what PC gamers need to do

Firefox 115 is the last build that will receive security fixes on Windows 7, 8 and 8.1

This caught my attention because plenty of PC gamers still limp along on older Windows installs – whether to keep an ancient GPU working, preserve a custom toolchain for mods, or avoid a Windows upgrade that breaks peripherals. Mozilla just confirmed that Firefox 115 is the final supported release for Windows 7, 8 and 8.1, and the Extended Support Release (ESR) that’s been delivering critical security patches will stop getting updates at the end of February 2026. That deadline matters now: once ESR stops, any bugs or security holes in the browser on those OSes go unpatched.

• Key takeaways: Firefox 115 is the cutoff; ESR security support ends Feb 28, 2026.
• Mozilla urges users to upgrade to Windows 10/11 or migrate to Linux if hardware can’t handle newer Windows.
• Switching to another mainstream browser won’t help – Chrome and Edge already dropped Windows 7/8/8.1 months or years ago.
• Downloads now steer legacy Windows installs to the final ESR; new Firefox builds simply won’t run safely on those older OSes.

Breaking down what actually changed

Mozilla updated its support page to lock Firefox 115 as the last compatible version for Windows 7, 8 and 8.1. If your machine is still on those OSes, Firefox will auto-migrate you to the ESR branch so you keep receiving patches until the ESR itself reaches its end-of-life at the end of February. After that, Firefox releases will no longer include security fixes for those systems.

Importantly, Mozilla’s notes and the download flow now detect legacy Windows installs and steer users to the ESR build (32/64-bit). That effectively blocks newer, actively developed builds from being installed on those OS versions – a hard line rather than a suggestion.

Why now — and why Mozilla finally set a firm deadline

Microsoft ended mainstream support for Windows 7/8/8.1 back in 2023, and keeping a modern browser running safely on unsupported OSes is expensive. Mozilla tried extensions to its timeline before — ESR deadlines slid a few times — but the security risk and maintenance cost of patching legacy APIs eventually outweigh the benefits. With Chrome and Edge already gone from those OSes, Firefox was the last mainstream browser still offering an escape hatch.

What this means for PC gamers

For gamers, this is more than a browser story. Many game launchers, web-based overlay tools, and in-browser indie games rely on a secure, up-to-date browser stack. Running an unpatched browser on an unsupported OS raises your exposure to drive-by exploits, compromised web-based game tools, and credential theft for accounts tied to Steam, Epic, or other services. In short: staying on Windows 7/8/8.1 after the ESR ends is a security gamble — you’ll be using a browser that won’t get fixes for new vulnerabilities.

Mozilla recommends upgrading to Windows 10 or 11 where possible. For truly ancient hardware that can’t reasonably run modern Windows, Mozilla explicitly lists Linux as an alternative — and yes, Firefox is the default browser on many popular distributions, so that’s a practical migration path for technically comfortable users. But switching an entire machine to Linux isn’t trivial for everyone; driver support, anti-cheat systems, and some games can still be hurdles.

What to watch next

• Final ESR security update release (expected by Feb 28, 2026). Install it immediately if you can’t upgrade right away.
• Post-EOL support requests and how many users migrate to Windows 10/11 or Linux.
• Whether hardware vendors or third parties step up with secure alternatives or migration tools for older gaming rigs.
• Traffic spikes for Linux distro downloads from users looking for a safer path off legacy Windows.

TL;DR

Mozilla has drawn a line: Firefox 115 is the last supported release for Windows 7, 8 and 8.1, and ESR security updates end on Feb 28, 2026. If you run games or game tools on those OSes, upgrade to Windows 10/11 or consider moving to Linux — after the ESR cutoff, your browser will be left exposed to new vulnerabilities.