I'm a novice at Linux, but try on old PC this: help>moretroubleshootinginformation, scroll down to Profiles, click 'about:profiles' and this should show you the exact location of your profile. Exit Thunderbird, and copy that profile to new PC. Then, repeat the steps in new Thunderbird, and after clicking 'about:profile' you should see a button 'create profile' in upper part of screen. Click that, enter a name (first), and then browse (second) to locate and select your preferred profile. That should do it.

David,

Thank you for your response, however I tried this from one of the posts on the web.

On the old system this works perfectly, and that is the directory that has been restored to the new PC.

Sadly on the new PC, the "Open Directory" button in Profiles does not do anything - very frustrating.

I have tried running 'thunderbird -profilemanager" in all the restored directories down to 'Mail'. I have also tried to run the profile manager with redirecting the profile directory name to the above command as in:-

  thunderbird -profilemanager < profiledirectoryname

None of this made any difference.

Thunderbird starts by wanting me to recreate everything.

I have even copied the old profile directory to the ~.thunderbird directory, all to no avail.

Okay, here's a wild thought, possibly useless. When TB asks to create new email account, click the 'home' tab at top. Then right-click and activate 'menu bar'. Then click help>moretroubleshooting information and scroll to Profiles and click 'about:profiles'. That should at least show you where TB wants the profile to be. If you can copy your old profile to same location, then maybe Linux will let you select it. I'm ignorant of Linux directory structure for TB, but this idea may work. Good luck.

I have gone into the area you describe Home > Menu Bar > help > moretroubleshooting information > Profiles > about:profiles.

There I see four directories - two under 'Profile: default-default', which has a number files & directories, and two under 'Profile: default', which has only two files.

The "Open Directory" button does nothing in all cases - very disappointing!

The 3 directories in 'Profile: default-default' directory have three counter part directories in the existing backup profile - cache2, safebrowsing and startupCache.

The old system only had one "SixRandomDigit.default" name directory, now, by the look of the 'about:profile' on the new system, there are four directories.

I am assuming that in order to be able top use the old profile and POP3 data stored on the backup, some of the old files will have to be split across the different directories.

Where can I get information on where to put these files - old directory structure listing can be provided (too many files).