Look on your desktop. Do you see a folder called; Old Firefox?

https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Look in the Old Firefox folder. Are there folder(s) in that folder? Open the folder with the latest date.

Dixie83 said

Found a folder that says "Old Firefox Data," but does not have all my bookmarks in there. Created a new profile and tried copying what bookmarks were there, but still don't see anything but Mozilla's bookmarks in the browser.

Hi Dixie83, I know this is frustrating!

Bookmarks

Firefox has a folder named bookmarkbackups that you might have copied from. The pattern of those file names is:

bookmarks-2016-10-31_9876_gibberish==.jsonlz4

That is the date followed by the number of bookmarks in the file.

If you found a file that looks up-to-date, you can restore it to your new profile. Just copying from the old backup folder to the new backup folder doesn't kick off the restoration. This article has the steps:

Restore bookmarks from backup or move them to another computer

If that works, you're done! Unless you want other data, too.

Complete Undo

There is a rather involved way to roll back a Refresh. Sadly, I'm not aware of any tool to automate this. Deep breath:

Check inside the "Old Firefox Data" folder that Refresh adds to your desktop for a folder with a semi-randomized name. If there's only one, that probably has your old settings and add-ons. If there's more than one, you'll want to work with the one that was updated most recently.

Once you have identified the profile folder you want to restore, here is my suggested "old profile resurrection procedure":

Overview

These are the steps described in more detail below:

1. Create a new Firefox profile (Firefox 47+)
2. Remove everything from that new profile folder
3. Copy in everything from the old profile folder

Create a new Firefox profile (Windows)

In Firefox, type or paste about:profiles in the address bar and press Enter/Return to load that page.

Click the "Create New Profile" button and assign a name like OldSettings. Ignore the button for changing the folder location and click Finish.

Next, scroll down and below the Profile: OldSettings box, click the "Set as default profile" button.

Then scroll back to the top of the page and click the "Restart normally" button. This should exit Firefox and start Firefox up in that new profile.

Open the New Profile folder in Windows Explorer

Firefox in the new profile should look like a factory fresh installation. Open the Troubleshooting Information page using either:

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

In the first table, click the "Show Folder" button. Firefox will launch your brand new profile folder in Windows Explorer.

Leaving that folder open, switch back to Firefox, and Exit using either:

• "3-bar" menu button > "power" button
• (menu bar) File > Exit

When Firefox closes, the profile folder should be front and center, or you can activate it using the Task bar.

Copy Old Data in Place of New

In that new profile folder you just popped open -- NOT the one on your desktop -- select all the contents (you can use Ctrl+a) and delete (you can press the Delete key on the keyboard).

Leaving that window open, open or switch over to your Old Firefox Data folder. Drill down into your old profile folder. (At this level you should see a folder named bookmarkbackups among many other things.)

Select everything (Ctrl+a) and Copy (either right-click > Copy or Ctrl+c).

Switch to the empty new profile folder in other window and Paste (either right-click > Paste or Ctrl+v). This may take a minute since some of the files are large.

Start Firefox

Firefox should start up in that "new" profile with the resurrected old profile data. Success?

Found the bookmark backups folder. It had about 8-10 bookmarks, nowhere near all the bookmarks I had. Plus, after moving the bookmarks in that folder to the new folder, they still don't show up when I try to access bookmarks in the browser. Going to try the complete undo shortly. Have to put my kid to bed and finish up some stuff to be able to close firefox.

jscher2000, the Complete Undo worked! Thank you!