OLEXP: How to Back Up the Outlook Express Address Book and Mail FoldersHow to Back Up or Copy Your Outlook Mail, Contacts and Other Data
That should help you find them. Since your Outlook is associated with your own email the program looks for yours in its own location. Those directions may not totally work in a direct way as you may have to find or change the associations of the drive/paths. Use of Windows Explorer may be needed to browse to the locations on his HD.
May have been better to go to the XP forum section and post how to fix the "broken" PC as re-installing XP may or may not wipe out the files unless the data was stored in a XP generated folder. That's why when I install some programs I change the default path to prevent an OS from erasing them. Many graphics programs may put saved images in the My Pictures folder which would be erased on a full install where the HD is formatted. GTG might be able to get you through an install that repairs the OS only depending on what is "broken".
Edited by AstraNut, 05 September 2010 - 01:46 PM.