Query a table using Code First and WinForms

Question

I have 1 user in table Users. I simple want to query all records in that table. I want to populate the list variable.

Database: TestTF

Table: Users UserId int IdentityField UserName nvarchar(64)

App.Config

<configuration>
    <configSections>
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
        <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=5.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </configSections>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
  </startup>
  <connectionStrings>
        <add name="TestEF" connectionString="Data Source=.;Initial Catalog=TestEF;Integrated Security=True" />
  </connectionStrings>
  <entityFramework>
        <defaultConnectionFactory type="System.Data.Entity.Infrastructure.LocalDbConnectionFactory, EntityFramework">
      <parameters>
        <parameter value="v11.0" />
      </parameters>
    </defaultConnectionFactory>
  </entityFramework>
</configuration>

TestEFContext.cs ( The context being used )

public class TestEFContext : DbContext
{
    public DbSet<User> Users { get; set; }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {

        base.OnModelCreating(modelBuilder);

        modelBuilder.Configurations.Add(new UserConfig());
    }
}

UserConfig.cs

public class UserConfig : EntityTypeConfiguration<User>
{
    public UserConfig()
    {
        HasKey(x => x.UserId);
    }
}

User.cs

public class User
{
    public int UserId { get; set; }
    public string UserName { get; set; }
}

Code in the WinForm:

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
        TestEFContext ctx = new TestEFContext();

        List<User> list = (from d in ctx.Users
                    select d).Take(5).ToList();

        foreach (User user in list)
            Debug.WriteLine(user.UserName);

        this.comboBox1.DisplayMember = "UserName";
        this.comboBox1.DataSource = list;
    }