The latest and final version of that officially supports Windows XP (English) is Firefox 52.9.0 ESR (Extended Support Release), which was released on June 26, 2018.
Because Microsoft ended support for Windows XP in 2014 and Mozilla ended support for this version in 2018, using Firefox on XP today presents significant security risks. Final Version : Firefox 52.9.0 ESR. Firefox English Windows Xp
: Only the 32-bit version is compatible with Windows XP; the 64-bit version of Firefox requires Windows 7 or later. The latest and final version of that officially
Official downloads are no longer available on the main Firefox homepage, but can be found via Mozillaβs Archive: Navigate to the Mozilla FTP/Archive. Select the or English (GB) folder. Download the file named Firefox Setup 52.9.0esr.exe . Run the installer on your XP machine. Current Limitations & Security Risks Firefox new for an XP laptop - Mozilla Support : Only the 32-bit version is compatible with
: A Pentium 4 or newer processor with SSE2 support is recommended. Download and Installation
: You must have at least Windows XP SP2 or SP3 installed to run this version.