64-bit from the User Agent entry in that section: So if the version numbers on your computer are the same, you can determine 32-bit vs. Now that the 64-bit version has been officially released, it carries the same version number as the 32-bit version. The Application Basics section at the top will show you the version you're running. If you have the menu display turned on, this is also accessible under Help | Troubleshooting Information.
In Firefox, type about:support in the the URL window.
