Looking for file related to saving Thunderbird session tabs

[conceptualclarity1]

I like to have multiple tabs open in Thunderbird and to have that tab configuration reset itself on the next restart. Of course crashes will sometimes cause that tab configuration to be lost. I figure there must be a file in an application data folder somewhere that has the job of saving that tab configuration from one session to the next. (How else could it be saved?) I'm interested in finding that file because I would like to back it up to another drive so I can restore it after a crash.

Can anybody tell me where that tab configuration file for Thunderbird is found?

FYI, because I'm on XP (I know, I know, get off it; I certainly intend to as soon as I can), I have to use Thunderbird 45.8

[DanRaisch]

This may be what you are looking for -- http://kb.mozillazine.org/Localstore.rdf