The only versions you update to are 3.6.28 (which will be dropped from support in a few weeks) or Firefox 11. I'd recommend either 11, or at least start planning for it. Is there a specific reason you don't want to upgrade to 11, I can try to help.

Tylerdowner, thank you for the answer which you posted on 4/1/12. I don't have anything specific against Firefox 11; I simply prefer to use "aged" software which has had some time to "mellow," i.e., stabilize. In other words, I want the safest and most reliable version. To me, that means a version which has been in use for several months and has gone through at least half a dozen minor updates. I would have updated long ago, but Mozilla began issuing new releases of Firefox so rapidly that none of them matured to a level at which I felt confident in committing to it.

   While researching in Firefox Support before posting this question, I landed on a Downgrade page which offered to let me downgrade to Firefox 3.6.  This caused some head-scratching until I realized that it was telling me, "You are using the oldest supported version of Firefox.  Therefore, downgrading is impossible."  I suggest that you add such a message to cover this situation.
   It appears that I could update to the latest version of Firefox, then downgrade to whatever version I want, but this seems like a silly waste of time.  Why not let me see the list of available installers, choose the one that I want and go directly to it?

Chandlabs, I agree. Although most volunteer helpers are advised not to recommend older Firefox versions due to unpatched security exploits.

Although I do believe in giving the user what they want because you are a grownup and can make your own decisions. Of course you're aware and accept the risks mentioned above by Tyler so here is a listing of all the older Firefox versions:
ftp://ftp.mozilla.org/pub/mozilla.org/firefox/releases/

Be advised you'll have to browse thru a few folders for each release. Example:
ftp://ftp.mozilla.org/pub/mozilla.org/firefox/releases/8.0/win32/en-US/

So you'll have to find the win32/en-US/ folders for each release.

Also, with the new Rapid Release cycle, the updating process has changed. For example, the firefox 8 that was released several months ago is the same Firefox 8 there is today. For some of the releases there may have been a minor release to fix one or two major issues, but usually known bugs waited until the next release to be fixed. (Example, if a bug was in Firefox 5, it wasn't fixed until 6, etc.). So unlike before, when you could run Firefox 3.5.x for seeks after 3.6 was released, and the older version still got updates, that story has changed now.

There is a downgrade to Firefox 3.6, that was left for organizations until we had figured out a strategy to support them. Something you may be interested in is the Extended Support Release of Firefox. Right now, it is based off firefox 10, and will receive minor updates for a year, then will be upgraded to a ne version (example, next year it will be Firefox 17 most likely) if you want something that isn't changing that much but still has the most recent security fixes.

http://www.mozilla.org/en-US/firefox/organizations/

Noah_SUMO, thank you for the answer which you posted on 4/4/12. I explored the link which you supplied. It was interesting, but now that I understand that superseded versions of Firefox are no longer supported in parallel with the current version, I am no longer interested in using a superseded version.

   Tylerdowner, thank you for the explanation of the Rapid Release cycle and the Extended Support Release, which you posted on 4/4/12.  I explored the Extended Support Release page at the link which you supplied, and the Enterprise Working Group Mailing List subscription page.  I decided that Enterprise is too heavy-duty for me right now, so I bookmarked these pages for future use when I have an IT staff.  Then I took the plunge and updated to Firefox 11.0.  Now that I understand that under the new Rapid Release system, a new release is not necessarily a major revision, I don't mind updating regularly.
   It certainly is nice to know that help from real, live people is available if I really need it.  I'm sure that I wouldn't get anything like this from Microsoft.

Hi. I'm in the same boat as chandlabs here. I've been using 3.6.28 for quite some time now, and don't much want to upgrade. However you have convinced me that I probably should. My biggest fear is that an upgrade straight to 11 will not keep the tags and notes on my Bookmarks. I have spent some time to get them the way I want them. The fear is justified. I exported them to another pc. This one was running 11. But the tags and notes for the bookmarks didn't get copied over. this is why I haven't upgraded yet.

Hi Gidtrina, could I recommend trying a different test?

First, create a new profile on your Firefox 11 to avoid overwriting your existing Firefox 11 bookmarks. Unless you don't care, in which case you could skip that step.

Close Firefox and start up in the Profile Manager as described in Managing profiles. Any time you want to switch profiles, close Firefox and return to this dialog.

Next, rather than moving your Firefox 3.6 bookmarks using the export to HTML method, try importing one of your backup (.json) files as described in this article: Backing up and restoring bookmarks | How to | Firefox Help.

Does that preserve your tags?

An HTML backup doesn't preserve tags and annotations, so if you used that format then that would explain the failure to import the bookmarks with its tags.

A JSON backup will preserve tags and annotations as posted above by jscher2000.
You only need to make sure that a JSON backup has a .json file extension, otherwise Firefox won't recognize the file.

You can also copy the places.sqlite database file to another computer or profile to get all the bookmarks and history.

Update. The .json file worked. all seems to have worked fine. So I suppose I'll be updating tomorrow. now lets hope all my Add-ons will still work. thanks all I appreciate the help.