You will have previously installed a beta version of Firefox. This will put you on the beta update channel, so whenever there is a new beta version of Firefox you will be offered to update to it. There have been a few beta updates for Firefox 5, and you will have installed the latest beta.

Unfortunately, the full version including the beta number is not being shown. That can be very confusing. Although I am at Firefox 5b3, the Help > About Firefox page shows Firefox 5.0. Also Options > Advanced > Update > "Show Update History" button does not show the beta number.

I have not received a notification about the new release of Firefox 5b5 (there apparently was no 5b4), but there is one outstanding post about an update failure for Firefox 5 by another user: https://support.mozilla.com/en-US/questions/832938?s=&as=s

You need to update the following. The Plugin version(s) shown below was/were submitted with your question and is/are out of date. You should update to avoid known security issues with the version(s) you have installed. Click on "More system info..." to the right of your question to see what was included with your question.

• Next Generation Java Plug-in 1.6.0_24 for Mozilla browsers

1. Check your plugin versions on either of the following links':
   • http://www.mozilla.com/en-US/plugincheck/
   • https://www-trunk.stage.mozilla.com/en-US/plugincheck/
   • Note: plugin check page does not have information on all plugin versions
   • There are plugin specific testing links available from this page:
     • http://kb.mozillazine.org/Testing_plugins
2. Update the Java plugin to the latest version.
   • Download site: http://www.oracle.com/technetwork/java/javase/downloads/index.html (Java Platform: Download JRE)
     • Be sure to un-check the Yahoo Toolbar option during the install if you do not want it installed.
   • Also see "Manual Update" in this article to update from the Java Control Panel in Windows Control Panel: http://support.mozilla.com/en-US/kb/Using+the+Java+plugin+with+Firefox#Updates
   • Removing old versions (if needed): http://www.java.com/en/download/faq/remove_olderversions.xml
   • Remove multiple Java Console extensions (if needed): http://kb.mozillazine.org/Firefox_:_FAQs_:_Install_Java#Multiple_Java_Console_extensions
   • Java Test: http://www.java.com/en/download/help/testvm.xml

If you open Help > Troubleshooting Information and then hit the about:buildconfig hyperlink and then hit the Built from hyperlink, you'll get a mozilla-beta changeset page that shows the build version number after Automated checkin.

A real convoluted way of seeing that information, which used to be visible in the About Firefox window in prior versions.

the-edmeister:

Thanks for that info. That's like having to call the telephone company to find out your number!

firefox 5.0b5 release

Thanx for the directions. My real concern was....

I closed all apps, put Win7 in "Logged Out" and left the building. Upon return I "Logged In" and opened FireFox 5 and immediately had a dialogue box... 'Do you want to install...' to which I agreed. Then realized I had not seen any indicator of a Firefox install though supposed it to be just that.

In concern, I inquired with support if they had pushed an update, without my being aware.

Just caught me off guard, thought I'd investigate.

@Helper7677
Firefox 4 & up versions are hard to verify exactly what is being used, as far as the UA is concerned. The "date" shows as 2010 01 01 for every version, there's no "language" identifier, the Gecko version number is gone - so all that we can go by is the Firefox version number, which doesn't say which beta version is installed. IMO, the developers went very overboard when changing things to prevent programs or extensions from tampering with the UA and messing too many users up with "compatibility issues". They should have "quit" when it came to eliminating the "extra" pref for the UA and not messed with the rest of that string, as it makes "our work" with helping Firefox users a bit more difficult.

@WillysBw
That update was probably downloaded when you were using Firefox before logging off Windows7, considering that you received the "Do you want to install..." immediately after you opened Firefox when you logged in again. Firefox program updates are checked for like 4 to 5 minutes after you open Firefox each day, not immediately upon opening Firefox - especially the 2nd time for the day. There is a "timer" in Firefox that delays checking for program updates until Firefox has been open for awhile, and to prevent Firefox from looking for program updates every time Firefox is launched - it keeps it to a maximum of once every 24 hours.

The Gecko version number is still there just that it is the same as the Firefox version now.

Unlike with RC builds before looking like it was the final, the last Beta deemed stable may end up being the final in this new more rapid release process.