"There was some message that popped up after signing back in that said I had used an older version of sync. "

Data saved with the older Sync 1.1 version isn't compatible with the latest Sync 1.5 version, along with the Sync 1.1 version servers having been shut down in late Sept or early October. There's a major difference in the manner that the data is encrypted, which is probably why you got that message. Plus - Sync wasn't intended to be used to backup data when doing a clean OS installation.

So are you saying that there is no way of recovering my bookmarks at all.

This is probably a long shot...

It might be possible to recover your bookmarks but only if you happened to have written down the "recovery key" from the old Firefox Sync. If you have that written down somewhere you could:

1. Install Firefox 28 (compatible with the old sync)
2. Sign into sync (including inputting the recovery key)
3. Once your bookmarks are back, disconnect sync
4. Re-install the latest Firefox

Without the recovery key there is no way to get your bookmarks back. This is because that key was used to encrypt your data. So Mozilla (nor anyone else) can read the data without it.

Another possibility would be if you had synced a second device (computer or Android device). Then you could disconnect that device from the old sync and sign it into your new sync account. Then the bookmarks would sync with your new copy of Firefox.

The big problem here is that we probably didn't do a good job of letting you know you needed this recovery key. This is not required in the new sync but that doesn't help you and for that I'm sorry.

- Michael

Raj22 said

So are you saying that there is no way of recovering my bookmarks at all.

I can't say that for sure. It mostly depends upon which version of Sync and the version of Firefox you last used before installing Windows 10.

Firefox 4.0 thru Firefox 28.0 used the 1.1 Sync version, which used a Recovery Key [as Michael Verdi mentioned] in addition to the Username [your email address] and a Password - three factors for logging into Sync.

As I mentioned first, the 'legacy' servers were shutdown over a month ago and AFAIK those older versions of Firefox wouldn't be able to connect to retrieve data; unless Michael knows how that data can be retrieved now. https://blog.mozilla.org/services/2015/07/31/shutting-down-the-legacy-sync-service/ https://blog.mozilla.org/services/2015/02/03/legacy-sync-migration/

Firefox 29.0 thru the current version uses Sync 1.5, which did away with the separate Recovery Key; users of Sync 1.5 only need their Username [email address] and their Firefox Account Password. The changeover occurred when Firefox 29 was released on April 29, 2014. Also, the Sync 1.5 account is called a Firefox Account, as it may apply to more that merely Sync - IOW other Mozilla services that you sign up for can use the same Firefox Account login.

To try to help you further we really need to know which version of Firefox you last used prior to installing Windows 10 and which version you have now. But from your initial posting I suspect that you are using Firefox with the Sync 1.5 now and may have been using an old Firefox 28 or older version previously - based upon this statement - "There was some message that popped up after signing back in that said I had used an older version of sync. "

Thanks for the responses. I did not write down a recovery key and I am not sure what version of firefox i had before. I think i am going to try downloading firefox 29 and signing in to sync and see if that works. Thanks again for the help.

Firefox 29 won't help as that version switched to the new Sync 1.5 version. Firefox 28 was the last version that only supported sync 1.0. I don't think that data stored on the sync 1.0 servers can still be accessed.

• https://blog.mozilla.org/services/2015/07/31/shutting-down-the-legacy-sync-service/