while in the old 98 PC is not an option (this would be an easy way to export the add book to a file), I would search for *wab on that drive. With any luck it will open and you can export it to file and import it into XPs OE.
I have two hard drives in a new box, OS Windows XP. Slave hard drive harvested from old computer which ran on Win98SE OS. How can I retrieve original address book as set up in Win98 Outlook express for use in XP?