Note: Linux and Mac users are generally already on 64-bit Firefox.
Windows users until August 2017 were generally running 32-bit Firefox, which is substantially less secure and more prone to crash than 64-bit Firefox.
Upgrade to 64-bit
- click Download Firefox at Mozilla.org. This is automatically the new 64-bit Firefox installer for Windows.
- Run the downloaded Firefox Installer. It will automatically install 64-bit Firefox, which can be verified from Firefox Help > About menu.
- Uninstall 32-bit Firefox by going to “Add and Remove Programs” and removing the “x86” Firefox