If it is outlook you will need to find and copy the .pst file(s). You can do search for *.pst. Once you have the pst you can mount it as is or import it to the new mail profile.
Move the backed up dbx files into the Outlook Express folder where the other, new dbx files are (do a search for *.dbx). Make sure they are not set to read-only. Move the folder.dbx file to another folder. Then start Outlook Express.
Can I suggest that while you have the affected hard drive slaved to a functional Windows PC, or while you have the affected computer booted to a Linux/WinPE environment, that you search for *.WAB files and copy them out too.
You can import from a WAB (Windows Address Book) into Outlook in much the same way as you can import messages from DBX files: http://support.microsoft.com/kb/286116