Mozilla, the maker of Firefox, had some good news this week for users still clinging to Windows 7 – Firefox ESR 115 support is being extended until March 2026.

Firefox 115 was the final supported version of the browser for Windows 7, 8, and 8.1. Although Microsoft has long consigned those operating systems to the dumpster, Mozilla has [1]kept the lights on via the Extended Support Release (ESR) channel, the last major browser maker to do so.

Microsoft ended support for the Chromium-based Edge at the start of 2023. In July 2023, Mozilla [2]said Firefox 115 ESR would remain supported until September 2024. It was later extended to 2025, and [3]now to March 2026 .

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"This extension gives users more time to transition while ensuring critical security protections remain available," Mozilla said.

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"We still strongly encourage upgrading to a supported operating system to access the latest Firefox features and maintain long-term stability."

The ESR program provides security updates. Whizzbang new features require a browser upgrade and an operating system update.

[7]Saved you a click: Firefox 142 offers AI summaries of links

[8]Some users report their Firefox browser is scoffing CPU power

[9]Mozilla flags phishing wave aimed at hijacking trusted Firefox add-ons

[10]Firefox 141 relieves chronic Linux pain in the neck

Extended support for Windows 7 ended in 2020. However, users could continue to receive security fixes via Microsoft's Extended Security Update program until January 10, 2023, the same date when extended support for Windows 8.1 ended.

2026 could be a big year for users of elderly hardware. As well as the end of support for obsolete versions of Windows, assuming Mozilla doesn't blink again, support is also [11]being pulled for 32-bit Linux with the release of Firefox 144. Firefox 145 will not support 32-bit Linux. The change will mean users unable or unwilling to change will need to move to Firefox ESR 140, which has 32-bit builds and will be supported until "at least September 2026."

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32-bit Linux has been on the way out [13]for years , and Mozilla noted that "32-bit Linux is no longer widely supported by the vast majority of Linux distributions, and maintaining Firefox on this platform has become increasingly difficult and unreliable."

And so the end has come. Or at least a move to the ESR channel, where support may or may not end in 2026. ®

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[1] https://blog.mozilla.org/futurereleases/2025/09/04/firefox-esr-115-support-for-windows-7-8-and-8-1-and-old-mac-os-versions-extended-until-march-2026/

[2] https://blog.mozilla.org/futurereleases/2023/07/06/firefox-support-for-windows-7-8-and-8-1/

[3] https://blog.mozilla.org/futurereleases/2025/09/04/firefox-esr-115-support-for-windows-7-8-and-8-1-and-old-mac-os-versions-extended-until-march-2026/

[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2aLtddE2sOwwjdIpMmXZjjgAAAAE&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0

[5] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aLtddE2sOwwjdIpMmXZjjgAAAAE&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0

[6] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33aLtddE2sOwwjdIpMmXZjjgAAAAE&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0

[7] https://www.theregister.com/2025/08/22/firefox_142/

[8] https://www.theregister.com/2025/08/13/firefox_ai_scoffing_power/

[9] https://www.theregister.com/2025/08/04/mozilla_add_on_phishing/

[10] https://www.theregister.com/2025/07/23/firefox_141_relieves_linux_pain/

[11] https://blog.mozilla.org/futurereleases/2025/09/05/firefox-32-bit-linux-support-to-end-in-2026/

[12] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44aLtddE2sOwwjdIpMmXZjjgAAAAE&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0

[13] https://www.theregister.com/2016/07/05/linux_letting_go_32bit_builds_on_the_way_out/

[14] https://whitepapers.theregister.com/