Well lets hope it finished moving the data to the Desktop to that OldFirefoxData folder as that is where you Profile, bookmarks and passwords and extensions and personification is.

• https://support.mozilla.org/en-US/kb/profiles-where-firefox-stores-user-data

uninstall Firefox. Then Delete the Mozilla Firefox Folders in C:\Program Files and C:\Program Files(x86) Then restart system. Then run Windows Disk Cleanup. (Note: This should be Pinned and run Weekly, If never done below expect 10's of gig's) Then run it again and click the button that says Cleanup System Files. Note: your Firefox Profile is saved. But you should make a back up before you do : Reinstall with Current Release Firefox 57.0.2 with a Full Version Installer

• https://www.mozilla.org/firefox/all/

Old Profile and how to work with it and new one :

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile
• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

fyi for the future :

• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer as HTML
• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Please let us know if this solved your issue or if need further assistance.

I uninstalled Firefox, deleted the Mozilla Firefox folders from program files, restarted my system, ran windows disk cleanup twice and clicked on cleanup system files. I went on internet explorer to download Mozilla Firefox with the current version 57.0.3 but it says " Firefox setup 57.0.3.exe couldn't be downloaded". What do I do now?

You could try downloading from a different Mozilla server to see whether it works better:

http://archive.mozilla.org/pub/firefox/releases/57.0.3/win64/en-US/

If you prefer a language/locale other than U.S. English, please click the .. link and that will take you up to a directory with all of the language/locale codes. The one that appears in the address bar when you use this forum is most likely the right one for you.

I went on

http://archive.mozilla.org/pub/firefox/releases/57.0.3/win64/en-US/

And it started the download process further than the last link but the error pop up shows again stating "your profile cannot be loaded. It may be missing or inaccessible." I still have the "old Firefox data" folder saved on my desktop. What can I do now? I read that I can create a new profile and copy over old data to the new profile, is that correct? My only concern is my saved bookmarks and passwords.

Okay, two more steps: (A) create a new profile, then (B) clear out its contents and replace them with a copy of the old profile data.

Well, each of those steps has more steps, so I suggest brewing a cup of coffee for this one. It may take about 10 minutes.

Go ahead and open your "Old Firefox Data" folder, double-click into your profile folder, and keep that Windows Explorer window to one side.

Create a new Firefox profile (Windows)

Copy the following command line:

firefox.exe -ProfileManager

Paste that into the Windows search box and press Enter to execute it. A small Profile Manager dialog should appear.

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

With that profile selected in the list, Start Firefox.

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 "Open 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, switch over to your Profile folder under Old Firefox Data. Here 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 restored old profile data. Success?

You are an absolute genius. Everything worked or appears to have worked. Firefox downloaded and I was able to restore my old Firefox data to the new profile just as you directed me. Thank you so much. I am not sure what I did to get me in this sticky situation but I hope I never do it again. I was originally trying to find a way to keep my browser privacy to remember logins and passwords. For some reason, every time I start Firefox, I have to go under options, then privacy & security, then click on the remember logins and passwords. Every single time. It doesn't automatically just keep the setting. I am not sure why.

Regarding the password setting, some external password manager software will turn off the ones built into browsers to avoid conflict/competition. It could be part of a security suite.

Is there any way to find the source or take it off? It looks like I have trial subscription for Trend Micro Internet security and McAfee security. And I also have windows firewall with advanced security and windows defender security center.

If you are not going to use the trial software, you can remove it and see whether that makes a difference.