How to open old Thunderbird Mailboxes 2007-2010 offline on the new Thunderbird? Or convert it to the new version.

   C:\Users\<Windows user name>\AppData\Roaming\Thunderbird\
   Copy the Roaming/'Thunderbird' folder 

   Exit Thunderbird - it should not be running. 

   C:\Users\<Windows user name>\AppData\Roaming\Thunderbird\
   Delete that new 'Thunderbird' folder from the 'Roaming' folder.
   Then paste the copied 'Thunderbird' folder (from old hardrive) into the 'Roaming' folder.
   Start Thunderbird.

I have several accounts in the Thunderbird I was using from 2007-2009 and I cannot open them on a new Thunderbird Install, I've tried the following procedure but it does not work. On old hard drive: Your profile should be located here: C:\Users\<Windows user name>\AppData\Roaming\Thunderbird\ Copy the Roaming/'Thunderbird' folder On new computer: Assuming you have installed Thunderbird and it has run once to create a default profile, but as yet no mail account or you want to use the old mail account settings, address books etc. Exit Thunderbird - it should not be running. Access default profile location: C:\Users\<Windows user name>\AppData\Roaming\Thunderbird\ Delete that new 'Thunderbird' folder from the 'Roaming' folder. Then paste the copied 'Thunderbird' folder (from old hardrive) into the 'Roaming' folder. Start Thunderbird.