Let’s do a full clean re-install;

Note: Firefox comes in three or more folders on all computers. They are;

Maintenance: (Programs Folder) <Windows Only> Firefox itself: (Programs Folder) And two folders in the profile of each user on the computer for each Firefox profile for that user.

If you remove the Firefox folder, the user profiles would not be affected.

Download Firefox For All languages And Systems {web link}

Save the file. Then Close Firefox.

Using your file browser, open the Programs Folder on your computer.

Windows: C:\Program Files C:\Program Files (x86) Note: Check Both Folders

Mac: Open the "Applications" folder. https://support.mozilla.org/en-US/kb/how-download-and-install-firefox-mac

Linux: Check your user manual. If you installed Firefox with the distro-based package manager, you should use the same way to uninstall it. See Install Firefox on Linux; https://support.mozilla.org/en-US/kb/install-firefox-linux

If you downloaded and installed the binary package from the Firefox download page, simply remove the folder Firefox in your home directory. http://www.mozilla.org/firefox#desktop ++++++++++++++++++++++++++++ Look for, and remove any Mozilla or Firefox program folders. Do not remove the Mozilla Thunderbird folder if there is one.

Do Not remove any profile folders.

After rebooting the computer, run a registry scanner if you have one. Then run the installer. +++++++++++++++++++++++++++ If there is a problem, start your Computer in safe mode and try again.

http://encyclopedia2.thefreedictionary.com/Linux+Safe+Mode This shows how to Start all Computers in Safe Mode; Free Online Encyclopedia

Thanks, but ...

"Let's do a full clean re-install" doesn't answer my question. Is Firefox still on my computer somewhere that I can't see? How could accessing a restore point have erased Firefox?

I don't want to go through all those steps if Firefox is still installed on my computer.

System Restore (or as I like to call it, Data Loss), normally doesn't remove program files. If you have Windows set to show hidden files and you ran a search for firefox.exe and didn't find it, then, for whatever inexplicable reason, it is gone.

https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files

What is crucial is your data, and not the program files which you can replace at any time. Make sure you still have your profile folder(s) after using Data Loss. See: Profiles - Where Firefox stores your bookmarks, passwords and other user data.

Jscher2000, you are the one who helped me put three rows of tabs in Firefox. If I reinstall the program, will those customizations still be there? I have forgotten the steps I had to take to do that, so it would be hard to do it again.

By the way, as far as I know, executable files are not hidden on my computer, so firefox.exe should have popped up in my search -- but then, the search function didn't seem to spend a lot of time on the search.

Do you recall whether that involved creating a chrome folder and userChrome.css file? If so, that would be in the profile folder.

Yes, that's where I created it. Will userChrome.css be overwritten, or is it safe during a fresh installation?

Thanks again for your help.

You can back up your profile folders as a safety, but the installer should detect them and re-use them automatically.

Note that using a Windows System Restore can also affect files in the profile folder and revert them to an older version (e.g. .ini and .js files and possibly others), so you should always be careful with using a System Restore. The same can happen to the Firefox installation folder (reverting to an older Firefox version in some cases).

I just reinstalled Firefox, and everything is gone -- bookmarks, customizations, everything. As long as I have to start over, I've decided to go back to the last version that uses Tab Mix Plus. Is that version 56.2? If not, can you tell me what version it is?

I'm not interested in hearing why I shouldn't go back to an old version. 56.2 is not so old. I started out with version 1, and Firefox has changed so radically since its beginnings that I don't recognize it. To say that I despise Firefox now is an understatement. It's ugly. It's clunky. It is illogically laid out. Where the hell is the menu bar?

Thank you.

I understand how you feel. I am still using v54 as my primary because I refuse to give up my add-ons.

Fred, any idea which version (before version 57) is the best for use with Tab Mix Plus?

Purebeads said

I just reinstalled Firefox, and everything is gone -- bookmarks, customizations, everything.

If you haven't already, could you close out of Firefox and do a normal Windows shutdown and restart to complete any pending updates and release any file locks.

If Firefox again starts up without your data, could you check whether your stuff is available in a different profile, as follows:

Profile Manager Page

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

This page should list at least one profile and could list many. (Each profile has two folders and one or more buttons. Do not use any Remove buttons!)

The profile that Firefox is currently using will have this:

This is the profile in use and it cannot be deleted.

Do you have another profile named default or default-longnumber listed on this page? If so, you can check whether it is the one you were using recently by clicking its Launch profile in new browser button.

If it isn't what you want, simply close that new window.

If it IS what you want, back on the about:profiles page, click the Set as default profile button for that profile so Firefox uses it automatically at the next startup.

Any progress so far?

To say that I despise Firefox now is an understatement. It's ugly. It's clunky. It is illogically laid out. Where the hell is the menu bar?

On Windows, the menu bar is hidden by default. To turn different bars on and off, you can use one of these methods to show the toolbar list and select the desired bars there:

• right-click (on Mac Ctrl+click) a blank spot on the tab bar (or the "+" button)
• (menu bar) View > Toolbars
  On Windows, tap the Alt key to activate the menu bar temporarily.
• in Customize mode > Toolbars button (see: Customize Firefox controls, buttons and toolbars)

To turn on the Menu Bar, or Bookmarks Toolbar, click it on the list.

What is clunky? What are you not able to rearrange that you want to rearrange?

Thank you, jscher, I will do what you ask, although not right at the moment. I'll report back later.

Purebeads said

which version is the best for use with Tab Mix Plus?

54 should work. I don't use it in mine.

You can check if you have orphaned profiles that aren't registered in profiles.ini and that doesn't show in the Firefox Profile Manager. You can check that by opening the current profile folder via the about:preferences page and go up one level (..) to see if there are unlisted profiles present.

• C:\Users\<user>\AppData\Roaming\Mozilla\Firefox\Profiles\<profile>\

If you have found an orphaned profile then you may want to recover some personal data or restore his profile.

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

You can recover an orphaned profile via these steps:

• use the Profile Manager to create a new profile
  https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles
• click "Choose Folder" in the Profile Manager
• browse to the location of this profile to register this profile in the Profile Manager and use this profile

See "Profile was moved or renamed":

• https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

Note you should never use "Choose Folder" to specify a folder that already contains files and that isn't a Firefox profile folder. Only use "Choose Folder" to recover an profile that isn't listed in the Profile Manager.

When I had rows installed in the latest version of Firefox, they didn't look very good. Since Firefox does not render pages very well, I am already using Opera and Chrome for the most important sites. But I still want Firefox for some pages. So I'm going back to version 56 so I can use Tab Mix Plus. Should I just go back to the latest release of 56, or is there a particular version that is known to work well with Tab Mix Plus? Thanks.