As per Microsoft: "When certificate services starts on a Certification Authority, the CA attempts to load the KRA(s) defined by the CA Administrator. If the CA is unable to load one or more KRA(s), event log messages will be generated; however, certificate services will continue to start. If the CA is unable to load a KRA(s) successfully as defined by a CA Administrator, the CA will deny all requests for key archival and not issue any certificates that have key archival defined in the certificate template. The following event log messages may appear in the Certification Authority’s Application Log when an error occurs in loading KRA certificates". See "Key Archival and Management in Windows Server 2003" for troubleshooting information.