Why isn't my certificate listed here?
Applies To: Windows SBS 2008
If the trusted certificate that you want to add is not listed:
It may not be in the Certificates\Personal store. Search for the certificate and import it into the correct certificate store. For information about importing the certificate, see How do I import an existing trusted certificate?
If you have chaining certificates, you must import all of them. Follow the instructions provided by the certification authority.