Windows Live Mail, Vista Mail, or Thunderbird 3 address books do not have an option to import from each other, and the address book titles and columns don’t match, so we kind of have to work around the problem.  Here’s how:

1. Download the Thunderbird Address Book Template I have made at:
   http://www.bakoweb.com/blog/Thunderbird_AdressBook_Template.csv (Right click and select “Save link as” then save it to your computer, remember where.)
2. Go into your Windows Live Mail or Vista Mail Address Book, and in the top menu, click “File” then select Export and select Coma Separated Values (.csv).  Then enter a name for the export and save it to the same folder you saved my Thunderbird Address Book Template.  Then select all the fields with a check mark, and click finished.
3. Open your Excel Spreadsheet program (if you don’t have a spreadsheet program use the free one at Google:  http://docs.google.com )  Open both the Thunderbird Address Book Template I made and your address book that you just exported in the spreadsheet program.
4. In the csv file of your address book you just exported, take one column at a time, copy/paste the ENTIRE column to the corresponding column of the Thunderbird Address Book Template I made.

   For example, copy the entire Name column on your address book export and past it to the Name column of the Template, copy the Business Email column of your address book and paste it in to the column marked Secondary Email of the Template.  Make sure you paste the columns into the corresponding columns of the Template, they won’t be in the same order, or called the same thing.  Do this for all the columns in the address book.

   To select an entire column, click the column Letter along the top of spreadsheet (A,B,C, etc.), then right click on it and select Copy.  To paste, select the column letter of the corresponding column, right click and select paste.

5. After you have finished copy/pasting all the columns into the Thunderbird Address Book Template, save the Template (again as a .csv).
6. Open Thunderbird and then open your Thunderbird Address Book, and in the top menu click “Tools” and select Import.
7. Then Select the Address Book check box, and click next.   Next select “Text File (LDIF, tab, csv, txt)” and click next
8. Down at the bottom of the new window, by the Open button, you will see a drop down menu that says “LDIF”, click this and choose “coma separated”, then browse to where you saved the Thunderbird Address Book Template that you modified with your address book, click it and click “Open”
9. In the next window that appears, select all the address book fields by checking them, and click OK.
10. Inside your Thunderbird address book, there should now be a new address book called Thunderbird Address Book Template, (or  what ever you named the Template that you modified with your addresses).  Select all of the addresses in this address book by holding down the shift key and clicking the first and last email address.  Then drag the email addresses to your Personal Address book of Thunderbird.  (You can delete the now empty new extra address book by right clicking on it and selecting delete).
11. All done