from
http://email.about.com/cs/oetipstricks/qt/et081201.htm
Some data cannot be exported, however, and you will lose address book groups as well.
To copy your Outlook Express address book to another computer using an universally readable CSV file:
Select File | Export | Address Book from the menu in Outlook Express (at the computer whose address book you want to copy).
Select Text File (Comma Separated Values).
Click on Export.
Save the exported address book with a meaningful name to a floppy disk, ZIP drive or something similar.
Click the Next button.
Select the fields you want to include in the exported Outlook Express address book.
Finally, click the Finish button.
Restore Your Outlook Express Address Book from the CSV File
Insert the storage medium with the copied Outlook Express address book into the computer that you want to copy the address book to.
Select File | Import | Other Address Book from the menu in Outlook Express.
Make sure Text File (Comma Separated Values) is selected.
Click Import.
Select Browse.
Locate the file you exported from the other computer.
Click Open.
Click Next.
Select the fields you want to import.
Click the Finish button.
