You can check if you have a C:\Windows.old folder with your personal data from the old Windows version.

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

"AppData" (XP: Application Data; Mac: ~/Library; Linux: ~/.mozilla) is a hidden folder.

• http://kb.mozillazine.org/Show_hidden_files_and_folders

If that is the case then you can recover your personal data and copy files to the current profile folder. For the Bookmarks you can copy the places.sqlite file (history and bookmarks) and the bookmarkbackups folder. You can recover more personal data. For the passwords you need logins.json and key3.db. The latter stores the encryption key (master password) needed to decrypt the passwords stored in logins.json (signons.sqlite is no longer used).

You can use this button to go to the current Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)
• http://kb.mozillazine.org/Profile_folder_-_Firefox

See also:

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

But I haven't a C:\Windows.old folder....I had to reformat the drive C :( MOD you have a way to help me retrieve the data it? Pls :((((

Did you have any problem signing in to Sync in the new Firefox installation? Did you request a new Password for Sync?

Type about:sync-log in the URL bar and hit Enter. Do you have any logs?

If so, open the oldest log and paste the contents of that log here: http://pastebin.mozilla.org/ Make sure you select more that a day. Then post the resultant URL in this thread.

the-edmeister said

Did you have any problem signing in to Sync in the new Firefox installation? Did you request a new Password for Sync? Type about:sync-log in the URL bar and hit Enter. Do you have any logs? If so, open the oldest log and paste the contents of that log here: http://pastebin.mozilla.org/ Make sure you select more that a day. Then post the resultant URL in this thread.

I don't understand what you mean....I had to reformat the drive C and installed new Windows then not Oldest log

When you set up Sync on a fresh installation and the initial Sync is completed, if there were any errors in the process an error log would have been created. No error log - Sync didn't have any detectable errors.

The 2nd screenshot appears to have sync'd no data at all - the server provided empty data files @1kb.

Did you request a new Password for Sync when trying to setup Sync on that new installation? If you did, your data was wiped from the Sync server. The new Password made the saved data useless; encryption for your data when it is off of your devices is created from the current Password. Change the Password and Firefox can't decrypt your data; the server is prepared for a fresh loading of data to allow the user to use the same email address.

Sorry, but Sync wasn't intended as a backup media for saving data when formatting a device and reinstalling everything. The encryption system used by Sync leaves no room for error. Based upon answering many other support questions similar to to yours, I can only guess that the account Password was changed prior to being able to sign in to the Sync service. When used properly to Sync multiple devices the user data would still be on another device, should there be user error or should other issues arise.

sorry but I do not change Pass. I have a lot of time sync and this is the only time the error occurred. I wait for data synchronization, but found nothing, so I decided to change the account previously synchronized gas still use firefox Code to sync. A moment later I changed the account synchronization so current but still do not see data downloading. P / s: I remember click forgot password once in the current account and have mail sent to, but I decided not to reset the password Thanks for caring