Outlook Express keeps its files in the (really labyrinthine) default location:
C:\Documents and Settings\USERNAME\Local Settings\Application Data\Identities\{HEX STRING UID}\Microsoft\Outlook Express. All the files are.dbx
You need to show Hidden & System folders to see it.
Use the OE import facility to import the folders (& messages therein).
The OE address book is (unhelpfully) stored by default in C:\Documents and Settings\USERNAME\Application Data\Microsoft\Address Book and is a .wab file. Just copy that to the corresponding new location.
If it's Outlook (non-Express), I'm sure that someone will be along to describe that shortly!
SD