Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

how do I restore my old information from the older computers' profile after I cinnected it to using sync (thinking that the both will merge)?

more options


I clearly understood the sync application wrong - I hadn't had confidence about getting everything right, when I was forced to wipe out one of my laptops (crash), when it comes to saving everything from my profile (e.g. under win8 for some reason my profile folder was in 2 places at the same time which confused me).

But also, I wanted to be convenient (automation) and clearly understood sync functionality wrong (really? - I am honestly surprised that no application was developed that syncs my adding already existing information for the profile of the next device which you're using /or at least app like sync doesn't ask whether to do so, before wiping off all what was in the browses on this device already - really poorly thought).

So my question is: - I activated sync on one machine - I did the same on the other (older) hoping that the information from the newer machine will just pour into existing profile on the older and both (histories, bookmarks, passwords, etc. - passwords not so important, but history and bookmarks at least) will be merged. - now clearly I lost (at least for now) ALL what was in the browser on my older computer (bookmarks and history from an over of half a year of work)... ;-0

What do I do with that? How do I restore ALL this information? Is there ANY way?

It's REALLY important for me - as I am a researcher and this was a pool through which I would be going through in my everyday work.

Really bad surprise. I did all in agitation (of my computer suddenly crushing - so clerly I wasn;t thinking straight and carefuly enough - otherwise I would back up the old computer browser first, before applying sync, to check what it does without any harm; but I felt "so cool and happy" about what it can do potentially do - "merge all my content from all the computer browsers" what I assumed with pure certainty that this is what it's doing - even for a second I didn;t think that it would do anything else, and "why it would do anything else?"/which clearly I got wrong and now I am in BIG TROUBLE/.

All Replies (2)

more options

Hi PiotrPoleski, Sorry you are in big trouble with Firefox. I will try to help and to explain.

You were correct. Firefox Sync should merge the data. Firefox Sync should not destroy or lose data.

It might lose data. That is a fault. There is very little that can be done if Sync loses data other than rely on other backups that you have.

I understand you have, or had, a Computer that had Windows 8 and Firefox on it. This Windows 8 computer had two Firefox profiles.

  • Do you still have those two profiles or good copies of the profiles ?
  • Do you expect those profiles to include important data ?
  • Is that the computer with half a years work on it ?
  • Do you still have that computer ?
    • And is it in full working order ?
    • With Firefox still installed and in use ?
    • Is it still Windows 8 or did you upgrade to Windows 10
    • Did you do a Firefox Refresh ?
    • You mention two profiles.
      Was one profile on the Windows Desktop?
  • I note you seem to be posting from a Windows 7 computer.
    • Is the Windows 7 computer the new one ?
      (Even though an older operating System)

Sync is for synchronising between existing devices. Sync is not designed to backup information to a server for use at a much later date to a device you are about to buy.

See also BUT please do not try anything else with Sync before you reply to my post.


  • What is your first language ?
  • In Firefox do the articles such as the one about - Refresh - redirect and display in your language ?

I have tried to write in short sentences.

You may be trying to translate between English and another language.

more options

There are 2 "Profile" folders. One in the Local path and the 'real' Profile folder in the Roaming file path, which has your Profile data. The 'Local' path is for the 4 types of "cache" files and other 'temporary' type files.

You shouldn't have lost your Sync data when Sync'ing as you described. All your data should have been merged, so the "old" PC would still have its own data with the "new" PC's data added to it.

There is no 'direction' control for Sync. All data gets Sync'd to the Sync server and is merged there, and then to the connected devices based upon what types of data in selected in Sync Options on each device. There is no device to device direct connection, the Sync server sits in the middle of all Sync activity.

The main reason for a user losing their data with Sync, that 'we' have run into here, is when the user requested a new Password or reset their Password for Sync which results in all data on the Sync server getting automatically erased from the server. That Password held the "key" to the encryption for the data that is one the Sync server, and with a new Password and "key" that data couldn't be decrypted, if it were to be sent to a device - that 'glob' of encrypted data was rendered useless when the Password was changed. But that wouldn't cause data that is already on any of the devices to be erased, unless (possibly) the user tried to 'force' the issue. And that is just a guess as to what might have happened in your case.

As far trying to fix that mess, your browsing history is probably gone for good on the "old computer" but you should still have up to 14 good Bookmark backup files; Firefox saves 15 days worth of bookmark backup files by default. And there's a count of the number of bookmarks in each backup 'hidden' in the file name. Look for backup files where a 3,4,or 5 digit number was high and then dropped to around 10 or less. Then select the newest with the highest "count" to Restore. The file names will look something like this - 2016-02-25_100_L4t9xz09002==.jsonlz4 - that 100 is the "count" of how many bookmarks are in that backup file. The "date" of the backup then the "count" number.

But before you do that "Restore" do an Export in HTML format to save the bookmarks that 'came' from the "newer computer" via Sync. The "Restore" will overwrite existing bookmarks and only 'restore' the bookmarks that were originally on only that "old computer". The HTML "Export" will append any existing bookmarks when you "Import" it.

Sorry that you have this problem, but I think you can at least recover your bookmarks from the "old computer" by doing the "Restore" and still have the bookmarks that came from the "new computer" by doing that HTML "Export" and then "Restore" from that computer and then doing an "Import" of that 'exported' HTML file.