Sorry, when a Refresh is interrupted, this can happen. Please start by creating a new profile. It won't have any of your data in it, but it will get us started.

You're going to start Firefox's Profile Manager using either the Windows Run dialog (hold down the Windows key and tap R) or the Windows 10 system search box. Paste the following and press Enter:

firefox.exe -P

This should launch a small window.

Click the Create Profile button, assign a name like OldSettings, and skip the option to relocate the profile folder. After creating the profile, select it and start Firefox in that profile.

I assume Firefox runs?

With Firefox running, you have a couple choices:

(1) Selectively restore some key data

You can manually copy important files from your old profile folder (like bookmarks and saved passwords) to your new one. The following support article lists the key files: Restore bookmarks, passwords, and data from an old Firefox profile.

(2) Completely "roll back" the refresh

There isn't any one-step way to do this, it involves copying ALL of your old data files from your old profile folder to your new one. Good news: complete data. Bad news: whatever was bogging down your Firefox before is likely to be back. Still, it could be easier overall.

Please start by finding your old profile folder. Usually after a successful refresh it can be found in an "Old Firefox Data" folder on your desktop. Inside, check for a folder with a semi-randomized name (several gibberish character, then a word like "default"). If there's only one, that probably has your latest 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, keep that open, and we'll open the new profile folder for copying.

Open the New Profile folder in Windows Explorer

Firefox in the new profile you created 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.

For a complete roll-back only:

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).

For a selective restoration only:

In that new profile folder you just popped open -- NOT the one on your desktop -- I suggest you right-click > Delete the files you intend to replace. This helps ensure you don't accidentally copy in the wrong direction and destroy your data. This may take a few moments to work through the list.

Copy Old Data in Place of New

Leaving that new profile folder 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.)

For a complete roll-back only:

Select everything (Ctrl+a) in the old profile folder 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.

For a selective restoration only:

Right-click > Copy a file you want to copy then switch to the new profile folder in other window and Paste (either right-click > Paste or Ctrl+v). If you removed the unwanted files first, you should not get any file replacement prompts, so if you DO get a prompt, there may be a problem with copying from old to new.

Start Firefox

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

jscher2000 said

Sorry, when a Refresh is interrupted, this can happen. Please start by creating a new profile. It won't have any of your data in it, but it will get us started. You're going to start Firefox's Profile Manager using either the Windows Run dialog (hold down the Windows key and tap R) or the Windows 10 system search box. Paste the following and press Enter: firefox.exe -P This should launch a small window. Click the Create Profile button, assign a name like OldSettings, and skip the option to relocate the profile folder. After creating the profile, select it and start Firefox in that profile. I assume Firefox runs?

Thank you so much for this suggestion. I have been able to get back in to firefox by selecting another profile (the version of firefox I'm running offers me a choice of 3 profiles when I start after abreset0. i assume this offering was from the previous which was successful. As it turned out 2 of the 3 profiles offered did NOT work, but thankfully the 3rd did. Otherwise I'd be sunk. I'm pretty much an idiot dealing with this stuff.

So jscher2000, thank you so very much! You have saved my sanity and my weekend.

teragrinch

Thank you so much for this suggestion. I have been able to get back in to firefox by selecting another profile (the version of firefox I'm running offers me a choice of 3 profiles when I start after a reset. As it turned out 2 of the 3 profiles offered did NOT work, but thankfully the 3rd did. Otherwise I'd be sunk. I'm pretty much an idiot dealing with this stuff.

So jscher2000, thank you so very much! You have saved my sanity and my weekend.

teragrinch