Hi, your old Firefox profile should have been placed on your desktop in a folder named "Old Firefox Data". please see - Refresh Firefox - reset add-ons and settings.

If your question is resolved by this or another answer, please take a minute to let us know. Thank you.

Thanks. No such folder was placed on my desktop. Note, I didn't "refresh firefox" but "refreshed" the laptop. Any other thoughts?

Hi, sorry, I misread - am not familiar with Win 8.1!

please see -

• Profiles - Where Firefox stores your bookmarks, passwords and other user data.

• Recovering important data from an old profile.

Hope that helps.

Thanks, but I'm no further forward. I should have also specified this is Mozilla Thunderbird, not firefox. Similar links exist for Thunderbird, but they all say A) data is held separately from program files (implying they wouldn't get wiped by a laptop refresh), and B) to recover them you need to have backed them up, implying the data is lost. I would be great to know what the answer is.

moving to the Thunderbird support queue