Now you see why we have posted countless times in this group that importing
is never the correct way to transfer Outlook data. You break links and lose
data.
If you're lucky, you may be able to fix some of the links you broke by
simply removing and re-adding the Outlook Address Book (you did not post an
accurate enough account of your version to tell if this is possible). If
not, you'll need to return to your backup and migrate the data correctly.
Re-use your data file. Do not import it.

To use another PST file (such as one from an earlier installation) and set
it to be the default for your current installation of Outlook, you will
first need to know the location and name of the PST file you'd like to use
as your new default. Then use the following directions, depending on version
and mode of Outlook:

Corporate Mode: (With Outlook closed)
- Control Panel > Mail applet
- Remove the  current Personal Folder service
- Readd the service, directing it to the new PST file location
- Restart Outlook

Internet Mail Only mode:
- File menu > Open > Personal Folders file > migrate to the new PST file
location to open it
- Right-click on the root of the new set of folders in the folder pane (View

- Choose Properties
- Check the "Deliver POP mail" box
- Quit & restart Outlook
- Now you can Close the PST file that you were previously using (R-click on
that pst folder while in Folder View and select "Close <foldername>
Folders"). If you have any information in your former PST that you'd like to
transfer to your new default PST, you can drag and drop from one to the
other before you close the old one.