On a 2k3 DC in the security log: 680,AUDIT FAILURE,Security,Wed Aug 17 14:53:43 2011,NT AUTHORITY\SYSTEM,Logon attempt by: MICROSOFT_AUTHENTICATION_PACKAGE_V1_0 Logon account: pc01017a$ Source Workstation: \\PC01017A Error Code: 0xC0000199 I removed the PC from the domain and put it back in. No change. Any ideas? Thanks for your help.

Hi, This problem may be caused by the security software on the client, such as Windows Defender or Forefront Client Security when they scan files that are stored in network locations. On the computer PC01017A, I suggest you temporarily disable the services of Windows Defender or Forefront Client Security service. Then, monitor if the problem continues. If not, please refer to this article to troubleshoot it: http://support.microsoft.com/kb/939361 Hope this helps. Regards, Bruce Forum Support Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

Thanks Bruce, We are using Symantec Endpoint Protection. I'll have to check its setup though I don't think it's supposed to scan network locations unless manually forced to.

Hi, Thanks for your feedback. Currently, please temporarily disable the service of Symantec Endpoint Protection on the client to test if the problem continues. If there is any update, please let us know. Regards, Bruce