Using the new search functionality in Outlook 2007 requires a specific Windows system component (Windows Desktop Search 3.0). By default, when this system component isn't present, users are prompted with a dialog box when Outlook starts that explains how to download the system component to install on their computers. In addition, other links are provided by default in Outlook to allow users to download the system component.
This setting allows you to prevent the dialog box from being displayed when the system component is not present on the user's computer and removes the other links provided in Outlook to allow users to download the system component.
Regardless of whether this setting is enabled, if the required Windows system component is not available, the Query Builder pane in Outlook is disabled.