In order to export mail to a PST file, EMS requires an Outlook MAPI to be present. Otherwise,
That means you must use 32-bit version of the Exchange Management Tools on an Outlook-installed workstation because 64bit EMS process cannot load 32-bit MAPI subsystem.
Thus, I quickly ran through a Vista 32bit set up steps.
1. Install Outlook
2. Install IIS Requirements
3. Install 32bit Exchange Management Tools, here.