There is no built-in way to do this. While you can copy sessionstore.js and sessionstore.bak from your active settings folder (current Firefox profile folder) and manually copy them back in later, this certainly is not guaranteed to work.

For robust session management, you could consider using one of these extensions:

• Session Manager - https://addons.mozilla.org/en-US/firefox/addon/session-manager/
• Tab Mix Plus (session manager feature) - https://addons.mozilla.org/en-us/firefox/addon/tab-mix-plus/

I have not tried either of those myself.

The forum software detected your Firefox as version 17. Is that correct?

Version 17 is not secure; Mozilla discloses security flaws after each new release. Is something holding you back from upgrading to Firefox 24-25? Please let us know so we can suggest solutions or workarounds.

If Help > About Firefox shows Firefox 24.0 or 25.0, you may need to clear the preference that is misreporting your version number. See: How to reset the default user agent on Firefox.

Note that Session Manager extends the built-in Firefox session Restore and thus can be more reliable than Tab Mix Plus that comes with is own implementation and that requires TMP to be installed and working properly.

This post was from my work site. I have no way to upgrade it. My home site has the current version.

Both jscher2000 and cor-el suggested the Session Manager Add-on. This has worked for me.

I wish I still had V17 on this machine! By pure accident, this machine was DOWNgraded to v19.02

What stops me from DOWNgrading to v24 / 25 are these problems: 1. The download box was moved from a separate pop-up box, and into the "Library" tab in v20. Screwing that up meant a great deal of lost functionality with the way that the download history could be displayed and handled. 2. The "find" function - for searching for within tabs- was completely neutered in (if I recall correctly) V21, as the same "find" dialog box no longer appeared across different tabs in the same window. Although a plug-in was supped to restore the original "find" functionality, it doesn't.

There's just two examples of many, of "fixing" things that were never broken!

I have the latest version loaded on another machine,. The application STILL hogs huge amounts of memory, STILL burns up memory when idle, STILL crashes at random, and is STILL grossly unreliable. I fail to see why the developers are failing to fix what does NOT work, and instead ruin the features that once did.

Hi CatsUncleNedThomas, if you would like personal advice on those issues, please start a new question. You can do that using the following link:

https://support.mozilla.org/questions/new/desktop/fix-problems

Scroll down past the suggested solutions to continue with the form (I think it has 3 different screens).