You will need a backup copy of the logins.json and key3.db files from the previously used profile folder and restore them in the current profile folder.

• https://support.mozilla.org/kb/Recovering+important+data+from+an+old+profile

Hi,

              Corel,
                         I have just uninstalled the troubled firefox, using Revouninstaler. Then I installed the new version. In the process, i have lost all the password data.
                  In my desktop, I have a folder called old firefox data. I elsewhere seen a thread by you, and tried trouble shooting as per your suggestion went to the Show Folder. I right clicked there, there was no context menu shown as previous version.
                     I have not stored the previous k3 and json file of the previous folders . Can i retrieve

Hi, Corel sir,

                     I also found that the K3.db file of old firefox data folder  is used by the current browser, which only has 16 kbs of data. So, is there any way , i could retrieve the password. 
                       I have just forgotten to take a copy of it, before uninstalling.

The files from the previous version might still be in your trash/recycling bin.

EDIT: Never mind -- read the next post

Your old profile is the the Old Firefox folder on your desktop. Including the password files. Open the current Firefox. Find out what the current profile is. Close Firefox. Copy everything in the Old Firefox folder to the new profile.

Hi, Fred

                     Should i delete the contents of the new profile before copying files from old firefox folder. I mean should i overwrite the contents of the new profile with that of old firefox data files

hi, Fred

                         Please this does not work. Since the new profile uses some data from the old firefox files. I tried. It shows only the present saved user sites and password saved

The names and passwords in the logins.json and signons.sqlite are encrypted with a key that is stored in the key3.db file. That is a basic key and the master password as an additional level of protection and you need to correct matching key3.db file. If you used a MP and you do not remember the MP then those passwords are lost and you would have to delete the key3.db and logins.json file.

Hi, Corel,

              I do not have a MP. I just saved the passwords for the forum and log on sites thro firefox alert . Then how do i retrieve. I tried to copy the contents of these two files from Old firefox data, which was not successful so far. It seems that firefox old data is somewhat used by the firefox lately installed. What are those same keys for present new profile?

What is firefox alert ? Do you mean sync?

Hi,

Fred, I mean the save password alert, when firefox prompts you to save the passwords for the site you wish to log on

Okay. the Password Manager will check it's data to see if the web site has an enter, and post it for you. If there is none, or you enter something else, it will ask if you want to add / update the information. Warning; sometimes the manager ends up with more than one entry for a site.

The Password Manager has to be active. Also, it will not operate in Private mode. Type about:preferences#security<Enter> in the address bar.

These are normal things. Now i have two profile, old and new. If i copy k3.db and js on from old format to new , it shows only recent passwords. I say that old firefox data is being used by new profie. Then what the new profile k3.db and json file doing in the new profile.

                        Could i retrieve the passwords from the old firefox data or is there any other way of doing so.

You should be able to copy the password files (logins.json, signons.sqlite key3.db) and copy them to the new profile. However, this would overwrite the current files. So anything in the new files would be lost.

These can't get your data back, but will help in the future.

These add-ons can be a great help by backing up and restoring Firefox

FEBE (Firefox Environment Backup Extension) {web link} FEBE allows you to quickly and easily backup your Firefox extensions, history, passwords, and more. In fact, it goes beyond just backing up -- It will actually rebuild your saved files individually into installable .xpi files. It will also make backup of files that you choose.

OPIE {web link} Import/Export extension preferences

One last thing. In the event that the passwords information is lost, you should record all information in a separate text file somewhere else on your hard drive, or written down. You can easily copy and paste if you need to do so. If you are concerned about someone else looking at that file, you can compress it using a password.

Hi, Fred , so There are 3 files to be copied to the new profile. Ok. I already copied the profile folder to some other drive before attempting this . I elsewhere read only two files. I will try your third file signon.sqlite and report

But Fred, i do not find any file named as signon.sqlite in the old firefox data or new profile. Would you say where to find the same?

The signons.sqlite was used in previous versions. In the current releases this file has been replaced by logins.json, so you only need this file and the matching key3.db file with the correct encryption key.

Hi, Corel

                Thanks for the information. But copying these two files from the old firefox file to new profile does not solve the problem.  It seems that the new firefox uses the old firefox data files.Pl clarify.