This is very helpful for families who share the same computer and share the same contacts in their address book. The solution is pretty simple and only requires a small Registry edit.

1. Log in as a user who has access to the address book you want everyone to share.
2. Click Start and click the Run command.
3. In the Run dialog box, type regedt32 in the Open text box. Click OK.
4. In the REGISTRY Editor, navigate to HKEY CURRENT USER\Software\Microsoft\WAB\WAB4\Wab File Name
5. Note the path to the WAB file. Write it down so you don't forget it!
6. Now logon as another user that you want to give access to the address book.
7. Open the Registry Editor again and navigate to the same Registry Key in step 4.
8. Double click on the entry you visited in step 4 and type in the new path. Click OK to make the change. Repeat the process for every user you want to have access to the address book.

Now everyone on the machine can use the same address book!