We are getting this message on our 32bit Windows 2008 Enterprise machine. I am thinking a reboot will fix this problem since it hasn't been rebooted for a while. This is our IIS machine. Further investigation using MMC, I added the certificates for the "Local Computer". I did see a few certs we have. The event log that is being generated referred to an expired cert (verified thumbprint). Any concern? Log Name: Application Source: Microsoft-Windows-CertificateServicesClient-AutoEnrollment Date: 9/6/2011 10:26:00 PM Event ID: 64 Task Category: None Level: Warning Keywords: Classic

Hi, Please first try the steps on this article: Event ID 64 — AD CS Certification Authority Certificate and Chain Validation http://technet.microsoft.com/en-us/library/cc774595(WS.10).aspx Hope it helps. Regards, Bruce