Finding these files can be difficult. Third-party "software archiving" sites often bundle malware with installers. The safest way to download these versions is through or the specific release archive.
Firefox 52.9.0 ESR was the absolute final version to support Windows XP and Windows Vista. Download Firefox 12-51 52 Esr
These browsers should be used strictly for testing, offline environments, or accessing legacy internal intranets that cannot be updated. They should generally not be used for online banking, shopping, or accessing personal email accounts. Finding these files can be difficult
and contain significant security vulnerabilities, making them unsafe for general web browsing. Where to Download Legacy Versions Mozilla maintains an Archive Directory that contains every public release of the browser. Firefox 12–51: Firefox 52
Mozilla officially recommends using their organization archives for ESR versions, but specific older releases like 52.9.0 ESR are often accessed via the . Key Version Details
Only download if the file is signed by "Mozilla Corporation" (right-click the .exe > Properties > Digital Signatures).
Can technically run these legacy versions, but they may conflict with modern Windows updates. Legacy Systems: