What happen if I dropped the Certificate-based SQL Server Logins
by accident
http://msdn.microsoft.com/en-us/library/ms181127.aspx
login like :
##MS_SQLResourceSigningCertificate##
##MS_SQLReplicationSigningCertificate##
##MS_SQLAuthenticatorCertificate##
##MS_AgentSigningCertificate##
##MS_PolicyEventProcessingLogin##
##MS_PolicySigningCertificate##
##MS_PolicyTsqlExecutionLogin##