I recently had to 'refresh' my Win 8.1 computer. Of course, the process erased all of the Thunderbird files and data. Fortunately, I had a recent backup on a separate HD. After re-installing Thunderbird, that's when I found out that all of the previous files and data were gone. So . . . a little digging around on your web site and a little experience, I went and copied all of the files from the old Mozilla folder to replace the 'new' ones and then tried the program - it opened as it was after the new install. So, I found the 'profile' data in the old HD - it was in a different folder name in respect to the new install. Now, being around computers fro more than 30 years, I copied the contents, not the folder, to the new folder, thus replacing the new files therein. (I figured the Registry would only recognize the new profile folder name, not the old one - maybe I'm right - who knows?) Opened up Thunderbird - wonderful - all is as was! IMO, it'd be nice of this info / process was a bit more clear in the support section and perhaps a script / program to make it painless. But, the info - and my experience - got me back to where I was before the 'refresh'. So happy now. BTW - I only use Thunderbird for RSS feeds, so there might be more to this process if another user uses it for mail and whatever else. But, at least its a start. Windows is still a pain. I hope that Win 10 is less so. THANKS for the support links and files - they helped. :)