If you reinstalled without having deleted the appdata\roaming\thunnderbird folder, it may still be there. Try this: - click help>troubleshootinginformation - scroll to 'profile folder' and click 'open folder' - you are now in windows file explorer, click the back arrow once - you should now be looking at the appdata\roaming\thunderbird\profiles folder - open the profiles folder - now, open each of the profiles there, looking for a file named abook.sqlite that has a recently used date. note the folder where you found it. - now, in thunderbird, click tools>import>import from a file - follow the prompts for addressbook until you reach the menu where 'sqlite' is an option. - click the sqlite option and then locate/select the abook.sqlite file you discovered - repeat the tppls>import steps to also import a file named history.sqlite from the same folder as the one in which you found the abook.sqlite file