Your first hurdle is to establish whether or not your backup process included the requisite files. Microsoft backup software seems to think that the ...\AppData\Roaming\ folder tree and its antecedents are unworthy of inclusion. https://support.mozilla.org/en-US/kb/profiles-tb Then I'd suggest that it's easier to work with the whole profile rather than cherry-pick bits out of it. It is not trivial to identify which folders and files you need, particularly with a complex mail folder tree. If you do want to import just specific mail storage folders, then I think the ImportExportTools add-on is well suited to importing selected folders and subfolders. But you still have the challenge of working out which is which. https://addons.mozilla.org/en-GB/thunderbird/addon/importexporttools/ Data that is imported in this piecewise manner should be regarded as "stateless" i.e. not belonging to any particular email account or identity, and so will be or should be imported into "Local Folders". Thereafter you can move it to where you really want it. If you're using IMAP then most of this is unnecessary, because all of your valuable email is stored on a server and automagically re-appears when the new installation of Thunderbird connects up.