: Pentium 4 or newer with SSE2 support . If your CPU does not support SSE2, the last working version is Firefox 48.0.2. RAM : At least 512 MB (1 GB recommended). Current Limitations
The latest version of Mozilla Firefox that supports Windows XP Professional (including 64-bit editions) is , released on June 26, 2018.
To run this version, your hardware must meet these minimums: : Windows XP SP2 or SP3 .
: You must use the 32-bit (win32) installer. Even if you are running Windows XP Professional 64-bit, the 64-bit version of Firefox requires Windows 7 or later.
: You can find this specific legacy version on the Mozilla FTP Archive or through the Internet Archive . System Requirements