Question: We have an automation test running on IE using WatiN. This test requires handling the logon dialog.
How I should process it by Watin?

Answer: 
In Windows 7, the Logon handler became a WPF component and no longer a part of the IE. I think this even applies to IE8 or higher already.

Below is the code we use for handeling these dialogs. It's something I wrote myself, so feel free to use it, as long as credit is given where due.

```
using System.Windows.Automation;
using System.Linq;
using WatiN.Core.DialogHandlers;
using WatiN.Core.Native.Windows;

namespace DialogHandlers
{
    public class Windows7LogonDialogHandler : LogonDialogHandler
    {
        #region Private Fields

        private readonly string _mUsername;
        private readonly string _mPassword;
        private readonly AndCondition _mListCondition = new AndCondition(new PropertyCondition(AutomationElement.IsEnabledProperty, true), new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.ListItem));
        private readonly AndCondition _mEditCondition = new AndCondition(new PropertyCondition(AutomationElement.IsEnabledProperty, true), new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Edit));
        private readonly AndCondition _mButtonConditions = new AndCondition(new PropertyCondition(AutomationElement.IsEnabledProperty, true), new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Button));

        #endregion

        #region Constructor

        public Windows7LogonDialogHandler(string username, string password)
            : base(username, password)
        {
            _mUsername = username;
            _mPassword = password;
        }

        #endregion

        #region Public Members

        public override bool HandleDialog(Window window)
        {
            if (CanHandleDialog(window))
            {
                var win = AutomationElement.FromHandle(window.Hwnd);
                var lists = win.FindAll(TreeScope.Children, _mListCondition);
                var buttons = win.FindAll(TreeScope.Children, _mButtonConditions);
                var another = (from AutomationElement list in lists
                               where list.Current.ClassName == "UserTile"
                               where list.Current.Name == "Use another account"
                               select list).First();
                another.SetFocus();

                foreach (var edit in from AutomationElement list in lists
                                     where list.Current.ClassName == "UserTile"
                                     select list.FindAll(TreeScope.Children, _mEditCondition)
                                         into edits
                                         from AutomationElement edit in edits
                                         select edit)
                {
                    if (edit.Current.Name.Contains("User name"))
                    {
                        edit.SetFocus();
                        var usernamePattern = edit.GetCurrentPattern(ValuePattern.Pattern) as ValuePattern;
                        if (usernamePattern != null) usernamePattern.SetValue(_mUsername);
                    }
                    if (edit.Current.Name.Contains("Password"))
                    {
                        edit.SetFocus();
                        var passwordPattern = edit.GetCurrentPattern(ValuePattern.Pattern) as ValuePattern;
                        if (passwordPattern != null) passwordPattern.SetValue(_mPassword);
                    }
                }
                foreach (var submitPattern in from AutomationElement button in buttons
                                              where button.Current.AutomationId == "SubmitButton"
                                              select button.GetCurrentPattern(InvokePattern.Pattern) as InvokePattern)
                {
                    submitPattern.Invoke();
                    break;
                }
                return true;
            }
            return false;
        }

        public override bool CanHandleDialog(Window window)
        {
            return window.ClassName == "#32770";
        }

        #endregion
    }
}

```
I know it has been a long time since this question has been answered, but I was having some trouble trying to use this code along with the IE11 (also at a browser configured with the PT-BR language), so I'd like to leave here my mods for those who might be interested or have been struggling with this as well.
\*sorry for my bad English!

\*\*watin ie11 authenticationdialog

public class Windows7LogonDialogHandler : BaseDialogHandler
 {
 #region Private Fields

```
    private readonly string _mUsername;
    private readonly string _mPassword;

    private readonly AndCondition _mListCondition = new AndCondition(
                                                new PropertyCondition(AutomationElement.IsEnabledProperty, true),
                                                new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.List));

    private readonly AndCondition _mListItemsCondition = new AndCondition(
                                                new PropertyCondition(AutomationElement.IsEnabledProperty, true),
                                                new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.ListItem));

    private readonly AndCondition _mEditCondition = new AndCondition(
                                        new PropertyCondition(AutomationElement.IsEnabledProperty, true),
                                        new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Edit));

    private readonly AndCondition _mButtonConditions = new AndCondition(
                                        new PropertyCondition(AutomationElement.IsEnabledProperty, true), 
                                        new PropertyCondition(AutomationElement.ControlTypeProperty, ControlType.Button));

    #endregion

    #region Constructor

    public Windows7LogonDialogHandler(string username, string password)
    {
        _mUsername = username;
        _mPassword = password;
    }

    #endregion

    #region Public Members

    public override bool HandleDialog(Window window)
    {
        if (CanHandleDialog(window))
        {
            var win = AutomationElement.FromHandle(window.Hwnd);

            var lists = win.FindAll(TreeScope.Descendants, _mListItemsCondition);
            var buttons = win.FindAll(TreeScope.Children, _mButtonConditions);

            var another = (from AutomationElement list in lists
                           where list.Current.ClassName == "UserTile"
                           where list.Current.Name == "Use another account"
                           select list).FirstOrDefault();
            if (another != null) another.SetFocus();

            foreach (var edit in from AutomationElement list in lists
                                 where list.Current.ClassName.Contains("UserTile")
                                 select list.FindAll(TreeScope.Children, _mEditCondition)
                                     into edits
                                     from AutomationElement edit in edits
                                     select edit)
            {
                if (edit.Current.Name.Contains("User name") || edit.Current.Name.Contains("Nome de usuário"))
                {
                    edit.SetFocus();
                    var usernamePattern = edit.GetCurrentPattern(ValuePattern.Pattern) as ValuePattern;
                    if (usernamePattern != null) usernamePattern.SetValue(_mUsername);
                }
                if (edit.Current.Name.Contains("Password") || edit.Current.Name.Contains("Senha"))
                {
                    edit.SetFocus();
                    var passwordPattern = edit.GetCurrentPattern(ValuePattern.Pattern) as ValuePattern;
                    if (passwordPattern != null) passwordPattern.SetValue(_mPassword);
                }
            }

            foreach (var submitPattern in from AutomationElement button in buttons
                                          where button.Current.AutomationId == "SubmitButton"
                                          select button.GetCurrentPattern(InvokePattern.Pattern) as InvokePattern)
            {
                submitPattern.Invoke();
                break;
            }
            return true;
        }
        return false;
    }

    public override bool CanHandleDialog(Window window)
    {
        return window.ClassName == "#32770";
    }

    #endregion
}

```