On 18 Jan 2014, "J. P. Gilliver (John)"
wrote in microsoft.public.windowsxp.general:

Given that (AFAIK, at least easily) OE won't run on 7 (let alone
8), how did you get TB to "import" all the OE folders? Does it
expect to find them already in certain places, or can you tell it
where (e. g. on a memory stick) they are [if so what files/folders
need to be copied]? I ask because I have previous experience of
some mail clients (not sure whether including TB) offering to
import everything from other ones, but then not doing so as they
weren't in the expected place and/or format.

The simplest method might be if your XP setup was still working. In
that case, Thunderbird will happily import all mail, address books, and
settings from Outlook Express. After you did that, you could then move
the whole Thunderbird profile to the new machine.

In my case, the old computer had died, but I still had access to the
files. I moved the OE message store directory with all the .dbx files
to the new machine. I can't remember exactly how it went, but I believe
that when I asked Tbird to import the messages, since it didn't find OE
installed, it let me navigate to the dbx files. I had to set up the
accounts manually.