[Lascaille]

This is all over the place. I've done this countless times when reinstalling laptops etc (because it saves redownloading 4GB worth of mailbox) and you just install thunderbird on the new machine, run it once, close it, make sure it closes properly then copy the Thunderbird directory from your appdata. Then you re-open it and it works.

[atoav]

I think it even "just works" when you create the directories manually, add the profile to it and then start Thunderbird.