Import email address

[mariner]

I'm using Firefox as my browser and Thunderbird for my e mail, as I've had to change computers and I changed from windows mail to thunderbird, I put all my e mail addresses on a memory stick, but I can't find out how to import them into Thunderbird can any one help please
Mariner

[Elaine ..Spain]

Tools / Import / Address book

... at least that is what it looks like!

[mariner]

Tools / Import / Address book

... at least that is what it looks like!

If only, it gives me alist of where from but not any I recognise i.e. Eudora, Outlook, Outlook Express, and Text files and computer illiterate that I am, it just don't make sense, so I'll print it and re enter one by one.
But thanks for your help.

Mariner