- Windows 10
- Windows 8
- Windows 7
- Windows Vista (32-bit Firefox only)
- Windows Server 2003 SP1 (32-bit Firefox only)
- Windows XP SP2 (32-bit Firefox only)
Please note that 64-bit builds of Firefox are only supported on Windows 7 and higher.
From Firefox 53 planned for April 2017, Windows XP/Vista/Server 2003 will no longer be supported. These users should migrate to Firefox ESR 52 once available (planned for March 2017).