To resolve the problem for future installations of Office, use the Custom Installation Wizard to edit the MST file.
Follow these steps:
1.On the Change Office User Settings page (page 10 of 24), expand Microsoft Outlook 2003, expand Miscellaneous, and then click PST Settings.
2.In the right pane, double-click Default location for PST files, then type the path that you want in the Default location for PST files box.
Example: type %USERPROFILE%\Local Settings\Application Data\Microsoft\Outlook\.
3.Click OK and follow the steps to complete the wizard. When you have corrected the MST file, deploy Office by using the correct MST file.
To resolve this problem for an existing installation of Outlook, specify the .pst file by using the Mail icon in Control Panel.
More information
here.