As of January 18, 2011, Microsoft will be signing antivirus engines used by Antigen with a new certificate in order to continue to ensure secure and reliable virus-engine updates. This will require a new certificate implementation on any Windows 2000 server running Antigen 9.0.

Please see the following Knowledge Base article for clear and detailed instructions on implementing this new certificate: As of 18th January 2011, a new certificate is required to continue updating virus engines for Antigen 9 installed on Windows Server 2000

Rob McCarthy, Sr. Support Engineer