The default installation path is invalid. If you are attempting an upgrade from a previous version of Exchange, ensure that ...

- The default installation path is invalid.  If you are attempting an upgrade from a previous version of Exchange, ensure that drive containing the Exchange installation is NTFS.  Otherwise, you must choose the action "Custom" or "Change" from the "Microsoft Exchange" component, then select a valid installation path by clicking the "Change Path" button, and then select the install action you want from the "Microsoft Exchange" component.