Backed up Thunderbird emails but when came to install on a new Windows 10 it was empty. Windows 10 was corrupted so had to reinstall Windows with MS help. Reinstalled Thunderbird had same /Profile name/nnnnnnnn.default folder as previously. New Windows program had folder Windows.old which contained the same default and included the emails presumably. Then Imported files from C:Windows.old but did not work and lost the *.default folder in the process and no new emails. Rather than try again, I would like some direction please. PS I did not backup the Address book so hope the file is somewhere in Windows.old.