I am trying to add a user to the Log on as a service propery in the Local Security Policy of my DC. When I do this I get this error "An Extended Error has occurred. Failed to save local policy database". If I click OK to the error everything looks OK, but when I go back into the property, the IIS AppPool\Classic .NET AppPool user and any other AppPool users are gone and I am unable to add them back in. I have tested this on two test networks with the same result. I tried to do this with a GPO, but have now lost the NT Service\All Services user too. I have checked the database and it is not corrupted. Any ideas on how to get the AppPool users and the NT Service\All Services user back in would be appreciated. Thanks Simon

Hi, May I know what Windows OS is your DC running now? Windows Server 2003 or 2008? Here are two related discussions can be referred to. An Extended Error has occurred. Failed to save local policy database. http://social.technet.microsoft.com/Forums/en-US/w7itprosecurity/thread/65f84208-6576-4cff-8b7e-02991b2ca823/ Failed To Save Local Policy Database http://setspn.blogspot.com/2010/09/failed-to-save-local-policy-database.html Note: Since the website is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information. If the issue persists, I suggest you contact Windows Server forum for further assistance.