Whilst performing an export using Search Exporter the following message is logged despite Outlook being the default mail client:
"Outlook is not your default client. Please make Outlook the default mail client before running this tool"
Corruption or problem with the Outlook installation or an unsupported Outlook version.
Verify you are running a 32 bit version of Outlook and ensure that version is listed in the release notes as a supported Outlook version for your version of Archive Manager.
If you have the correct version of outlook installed follow the steps provided in this Microsoft KB article: http://support.microsoft.com/kb/813745 to resolve corruption.