: It was the last version to support Windows XP and Windows Vista , though it remains functional on Windows 10 . Important Security Warning
: To prevent the browser from automatically updating to the newest (and non-NPAPI compliant) version, go to Options > Advanced > Update and select "Never check for updates." firefox 52 esr windows 10 download
: It was the final version of Firefox to support NPAPI plugins, such as Java , Silverlight , and Adobe Flash . Modern browsers have since removed this support for security reasons. : It was the last version to support
Using Firefox 52 ESR in 2026 poses significant . Because this version has not received security patches since 2018, it is vulnerable to modern web exploits. Using Firefox 52 ESR in 2026 poses significant
: Double-click the .exe file. If Windows 10 shows a "SmartScreen" warning (because the version is outdated), you may need to click "More info" and then "Run anyway."