Were all your other settings intact after the reinstall?

If No:

Please check your Windows desktop for a folder named Old Firefox Data. Do you have one? If you check inside, does it have a semi-randomly-named folder full of recently updated files? If so, hang onto this and we can discuss restoring this data.

If Yes:

First: Do not exit Firefox, or if you closed it, don't re-open it.

If Firefox is still up, check the History menu for "Restore Previous Session" and, if it's not grayed out, try that.

If that is grayed out or doesn't help, let's back up a few files. Here's how:

(1) To open your profile folder...

If Firefox is still running:

You can open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Show Folder" button.

If Firefox is closed:

Type or paste the following into the Windows Run dialog or the system search box and press Enter to launch Windows Explorer:

%APPDATA%\Mozilla\Firefox\Profiles

In that folder, do you see a semi-randomly-named folder? If so, click into it. If you find multiple such folders, find the one that was most recently updated.

(2) Copy out session history files

In your profile folder, scroll down and double-click into the sessionstore-backups folder. Save all files here to a safe location, such as your Documents folder. If not too much time has passed, we may be able to use them to recover your lost tabs.

(3) What files did you find?

The kinds of files you may find among your sessionstore files are:

• recovery.js: the windows and tabs in your currently live Firefox session (or, if Firefox crashed at the last shutdown and is still closed, your last session)
• recovery.bak: a backup copy of recovery.js
• previous.js: the windows and tabs in your last Firefox session
• upgrade.js-build_id: the windows and tabs in the Firefox session that was live at the time of your last update — this might be what you're looking for

Could you take a look at what you have and the date/time of the various files to see whether you think any of them would have the missing tabs?

Note: By default, Windows hides the .js extension. To ensure that you are looking at the files I mentioned, you may want to turn off that feature. This article has the steps: http://windows.microsoft.com/en-us/windows/show-hide-file-name-extensions

Thank you jscher2000.

I went through your steps and found both the upgrade and recovery files. Unfortunately, I did a restart and I did a second download and install, as the first one download/install kept hanging for some reason. So, I only found the tabs for the first install.

However, I saved your instructions for the next time this happens.

Thank you again, Dave

Usually when you reinstall Firefox, it detects whether it was already installed and re-uses your existing data. Could you check for one other thing: whether there are any other Firefox profile folders in the usual location.

You can open your current Firefox settings (AKA Firefox profile) folder using either

• "3-bar" menu button > "?" button > Troubleshooting Information
• (menu bar) Help > Troubleshooting Information
• type or paste about:support in the address bar and press Enter

In the first table on the page, click the "Show Folder" button.

Navigate "up" one level to the Profiles folder. Are there any other semi-randomly-named profile folders here that could have your missing tabs?