You have two choices:  1.  Install Outlook under Vista.  Versions 2003 and
later
run well under Vista; versions 2000 and 2002 run under Vista, but with some
problems.  Windows Mail needs to use part of it to be able to import the
.pst
files Outlook stores mail in.  Some, but not all, versions of Microsoft
Office
include Outlook:

http://us1.trymicrosoftoffice.com/default.aspx?re_ms=oo&culture=en-US

2.  Import the messages from Outlook to Outlook Express on your old
computer.  Then import them from Outlook Express to Windows Mail:

<http://www.askmehelpdesk.com/email/import-dbx-files-outlook-express-windows-mail
-vista-86458.html>

<http://www.vista4beginners.com/Migrate-from-Outlook-Express-to-Windows-Mail>

After you copy the files to a directory on the hard drive of your new
computer,
make sure the copies are read-write instead of readonly before you import
them
into Windows Mail.