pipe = new NamedPipeServerStream(_PipeName, PipeDirection.InOut, NamedPipeServerStream.MaxAllowedServerInstances, PipeTransmissionMode.Message, PipeOptions.None); PipeAuditRule auditRule = new PipeAuditRule(@"NETWORK SERVICE", PipeAccessRights.FullControl, AuditFlags.Failure); PipeAccessRule accessRule = new PipeAccessRule(@"NETWORK SERVICE", PipeAccessRights.FullControl, AccessControlType.Allow); PipeSecurity security = pipe.GetAccessControl(); security.AddAuditRule(auditRule); security.AddAccessRule(accessRule); pipe.SetAccessControl(security);The pipe.SetAccessControl(security) fails with System.UnauthorizedAccessException