Hi

In respect of both the Primary Password and the password for Firefox Sync, changing them clears data stored (in respect of Primary Password) and in sync between devices (in respect of Firefox Sync).

Do you have a backup of your Firefox Profile or have your bookmarks on a second device? If so it may be possible to recover them.

Thanks Paul Unfortunately the old computer is toast. I have all my files & pics, etc backed up. They're being restored now. I'm not sure why Mozilla can't verify my identity and turn the bookmarks & passwords back on.

In respect of a Primary Password - Mozilla has no record to be able to verify you with and the functionality is local to your device.

In respect of a Firefox Account password, Firefox Sync is designed to sync bookmarks and other data between devices, not as a backup. Where a password is lost, possible compromised, data being sync is cleared and would re-sync afterwards this protecting the data in transit.

So if I had remembered the password, all the bookmarks & passwords would still be gone?

I am still not sure which if the two passwords you are referring to, but if you mean the Firefox Account password - Firefox Sync is not designed to be used as a backup. It is designed to sync bookmarks, passwords and other data between copies of Firefox, typically between Firefox on a desktop computer and on a mobile device.

Is the hard drive from that device still healthy so you can possibly access it via an USB enclosure ?

Resetting the password for the Firefox Account because you do not remember the password will remove all data stored on the Sync server because this password is used to encrypt your data before it is uploaded to the Sync server and only this password or a possible recovery key can decrypt this data.