If you're comfortable with Windows File Explorer, you can do this: - on old pc, highlight the folder, rightclick and select properties. That gives exact location on drive - exit thunderbird and copy the file (NOT the msf) to extenal media - on new PC, click help>troubleshootinginformation - scroll down to 'profile folder' and cick 'open folder' - exit thunderbird - click the Mail folder and then the Local Folders folder' - past the copied folder here in local folders - restart thunderbird

David, I want to copy all my folders inc sub folders from PC A to PC B so I can access the emails for reference only. I need all the attachments too.

I think what I posted can be applied to that, but maybe I need more information. Thanks.

David, I cannot see " help>troubleshootinginformation" when i open thunderbird on my new PC. Also thunderbird is running Imap on new pc. How can i have it as pop3?

You cannot change IMAP to POP. Instead, you would need to create a POP account. You could keep the IMAP account or remove, as desired. Help is an entry on the hamburger menu in upper right.

Another approach would be to have the importexporttools NG addon on both computers. you could highlight the folder on old PC, select the importexporttools option to export eml messages with index and subfolders. eml and on new pc, highlight Local Folders, rightclick and select the option to import eml messages from directory and subdirectories.