Firefox 4 has reached end of life, no support, no fixes, and should not be used.

You can get the Google Toolbar to work for you in Firefox 5, see the ed-meister's reply to a question

• https://support.mozilla.com/en-US/questions/837473

I've never found that I needed the Google Toolbar, I can invoke the Google translator with bookmarklet, or any other web translator. I can use Firefox to check my spelling and can even check the spelling on created web pages.

• https://support.mozilla.com/en-US/questions/841081

You can make Firefox Firefox 5.0 look like Firefox 3.6.19, see numbered items 1-10 in the following topic Fix Firefox 4.0 toolbar user interface, problems (Make Firefox 5.0, or 4.0.1, look like 3.6). Whether or not you make changes, you should be aware of what has changed and what you have to do to use changed or missing features.

Firefox 4.0 should not be used, but just so you won't mess up your profile by reinstalling an older version. And your reason does not justify using 4.0.1 because you can turn off compatibility as provided in the first link above..

For those that really need an earlier version of Firefox, find your system and the Firefox version you want in releases, download and start the install.

• ftp://ftp.mozilla.org/pub/firefox/releases/

or with the latest of version 3

• http://www.mozilla.com/firefox/all-older.html

Note Mac OS X 10.4 user, and Mac OS X 10.5 users without Intel cannot upgrade to Firefox 4 or 5.

When reinstalling Firefox from a download, Firefox must be down once the installation starts. When the installation finishes, don't let the install start firefox for you. Instead end the install and start Firefox in your normal manner, thus preventing creating a new profile which does not have your bookmarks cookies, etc (but your old profile would still be around and would).

Google's response: [updated 07/19/2011 marked at bottom 0f their response ] provides alternatives.

Toolbar not available for Firefox 5 or newer versions : Install or uninstall - Toolbar Help http://www.google.com/support/toolbar/bin/answer.py?&&answer=1342452

But the ambiguity of if it ever would be updated, has now been made clear with a later statement from Google (see the-edmeister's reply) indicating that the Google Toolbar will never be updated for Firefox 5 and future Firefox versions.

The Google Toolbar "will not be supported on Firefox 5 and future versions."
http://googletoolbarhelp.blogspot.com/2011/07/update-on-google-toolbar-for-firefox.html

http://www.google.com/support/toolbar/bin/answer.py?answer=1342452&topic=15356%29

The Google Toolbar 7.1.20110512W version does work pretty good in Firefox 5.0 by using the Compatibility Reporter extension. But not every feature works 100%.
https://addons.mozilla.org/en-US/firefox/addon/add-on-compatibility-reporter/

http://googlesystem.blogspot.com/2011/06/enable-google-toolbar-in-firefox-5.html

Thanks Ed for removing the ambiguity.

This page is an easier way to download Firefox 4.0: http://www.mozilla.com/en-US/products/download.html?product=firefox-4.0&os=win&lang=en-US , as this links starts the download process asap.

I needed to upgrade to Firefox 4.0+ for an add-on that I really needed. However, I can't use Firefox 5.0, as I randomly checked 3 add-on's I had: "Firefox PDF", "Delicious Bookmarks" and "After the Deadline", and none of them worked with Firefox 5.0. In fact, I will have to download alpha versions, etc., to get these add-ons to work with Firefox 4.0.

Please see the following MozillaZine article:

"Using Google Toolbar features without toolbars"

http://kb.mozillazine.org/Using_Google_Toolbar_features_without_toolbars

@dmcritchie

Excellent article in the MozillaZine KB! I have never actually used the Google Toolbar either, but I have played with it a bit to see what it is all about to try to help users with at least the basics. Looks to me like you covered the alternatives quite good.

Thanks so much geejaye!

At first 5 was fine and I like some of the new features, but then I started finding more and more glitches and bugs and things I wanted to do that I couldn't.... It was just getting to be a real pain. So, I decided to go back to 4 until they worked the kinks out of 5. They've done and amazing job of erasing it from the net though, haven't they. I've been searching for ages for a link to download old reliable 4 and this is the first I've found.

So, I'll sit tight with my out of date firefox until they can get the bugs in 5 worked out. *g*

Cheers mate!