*Outlook*-data are stored in *.PST files.
Check your backups.
When you re-installed, did you do it from scratch wir did you
over-install?
On case the latter you should be able to find the files in the hierarchy
of "Windows.old" in a subdirectory of "Users". Search for *.PST there.
If you can find the files, you'll have to re-install Outlook on order to
Import the data in WinMail (the import requires that OUTLOOK is
installed on the computer).