David, I think what I said is that the folders seem to be in the files you suggested / I mentioned but I couldn't post images of them to the forum. Something I don't get about the Browse button. I didn't have time to work on it today. Here's what I plan to try tomorrow:

Copy the Thunderbird profile from old PC to the HDD. Copy the old pop.earthlink.net folder and the old Local Folders folder to the HDD Install all three those to the new PC, using %appdata% for Thunderbird.

Edit the profile on the new PC so that the file paths in Account Settings point to the copied over files, i.e.:

   the path for Message Storage > Local Directory points to the pop.earthlink.net folder;
   the path for Local Folders points to the Local Folders folder.

Seems logical. Hope it works! Thanks for your patience!

Woo hoo! Successfully installed TBird on new PC today, 4/23/25 @ 3:42 PM EDT, with 21,564 historical messages! Some of those are extremely valuable to me! Also sends, receives, and has all address books.

I copied the "Thunderbird" profile on the old PC, using the %appdata% method and pasted it to the new PC. I then briefly brought up TBird and edited Server Settings to the files that contained my folders and Local Folders and closed TBird again. Then I moved those files to the new PC and finally brought up Thunderbird. Voila! The data was there!

Many thanks to David for patiently sticking with me!

DavidF

I was glad to assist. Free beer for everyone. :)

Here's a tip: do backups on occasion to ensure all is good. Here are steps I use:

BACKUP

1. ensure thunderbird is not running
2. enter %appdata% in search window on task bar and press Enter key
3. this should open windows file explorer in Appdata\roaming folder
4. highlight the Thunderbird folder and copy to external media

RESTORE

1. ensure thunderbird is installed and NOT running
2. enter %appdata% in search window on task bar and press Enter key
3. you should be in Appdata\roaming folder , copy&paste the exported Thunderbird folder there. This may prompt to overwrite an existing folder of same name. allow it
4. start thunderbird and all should be there

I may be mistaken, but I think the sequence was important. I think it's important to copy over the profile from %appdata%, then bring up TBird and edit the various pointers to local files then exit it again. I got restart messages at this point which ignored since I was going to restart anyway.Then exit TBird again, copy over the files and bring up TBird again. Something like that, anyhow. I'll buy the beer!

Using windows file explorer is the only way that guarantees the profile is copied 100%. When thunderbird copies, it edits as it goes.