https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer

Here is what I respond when asked how to transfer from one PC to another. I think it may apply here IF you have located the c:\users\<yourid>\appdata\roaming\thunderbird folder. If you do NOT have the thunderbird folder, let me know and I'll provide other steps. Here is the link for moving a profile in Windows when installed in default location: https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer here is the info in brief steps: # ensure thunderbird is not running on old machine # enter %appdata% in search window on task bar and press Enter key # this should open windows file explorer in Appdata\roaming folder # highlight the Thunderbird folder and copy to external media # ensure thunderbird is installed on second computer and NOT running # enter %appdata% in search window on task bar and press Enter key # 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 # start thunderbird and all should be there