After deploy in server, integrated Security works for all users but only one user does not work for one user

Question

hi
   i'd like to ask for help.here is a brief introduction.
      i publish a web project on a server(the name,"server-deploy"),(it connect with sql server datavvase with connection string  of database  "Trusted_Connection=Yes",with web config file <authentication
mode="Windows" />    <identity impersonate="true"/>
   there are some users whose Impersonae_clients_after_authentication are enabled. and most of them can connect to database via the deployed project .
  but one user,he was told 'NT AUTHORITY\ANONYMOUS LOGON', and according to even viewer("security of "windows log") of "server-deploy",it shows "Audit failure"(the Task category is "credential validation")
and here is some information
[ Name]  Microsoft-Windows-Security-Auditing
   EventID 4776
The computer attempted to validate the credentials for an account.
  PackageName MICROSOFT_AUTHENTICATION_PACKAGE_V1_0
  TargetUserName (user)
  Workstation (Workstation)
  Status 0xc0000064
   while when other user do login ,there is no log whose Task category is "credential validation".
  COULD ANY ONE CAN DO ME A FAVOR TO HELP ME?ANY HELP IS APPRECIAT. THANK U VERY MUCH IN ADVANCE :)
best regards
martin

Answer 1

and i made a small windows form application here
   private bool impersonateValidUser(String userName, String domain, String password)
            WindowsIdentity tempWindowsIdentity;
            IntPtr token = IntPtr.Zero;
            IntPtr tokenDuplicate = IntPtr.Zero;
            if (RevertToSelf())
                if (LogonUserA(userName, domain, password, LOGON32_LOGON_INTERACTIVE,
                    LOGON32_PROVIDER_DEFAULT, ref token) != 0)
                    if (DuplicateToken(token, 2, ref tokenDuplicate) != 0)
                        tempWindowsIdentity = new WindowsIdentity(tokenDuplicate);
                        impersonationContext = tempWindowsIdentity.Impersonate();
                        if (impersonationContext != null)
                            CloseHandle(token);
                            CloseHandle(tokenDuplicate);
                            return true;
            if (token != IntPtr.Zero)
                CloseHandle(token);
            if (tokenDuplicate != IntPtr.Zero)
                CloseHandle(tokenDuplicate);
            return false;
  and here is the code of buttonclick
 if (impersonateValidUser(user,psw,doman))
                if (!System.IO.Directory.Exists(this.textBox1.Text))
                    MessageBox.Show("not exist with imper");
                else
                    MessageBox.Show("exist with imper");
                undoImpersonation();
            else
                MessageBox.Show("fail login.");
   and i was told "exist with imper"(usually if Impersonae_clients_after_authentication is not enaled would told "not exist with imper" )