The following code is a complete XNA 3.1 program almost unaltered to that code skeleton Visual Studio is creating when creating a new project.

The only things I have changed are

• imported a .x model to the content folder of the VS solution.

  (the model is a simple square with a texture spanning over it - made in Google Sketchup and exported with several .x exporters)

• in the Load() method I am loading the .x model into the game.

• The Draw() method uses a BasicEffect to render the model.

Except these three things I haven't added any code.

Why does the model does not show the texture ? What can I do to make the texture visible ?

This is the texture file (a standard SketchUp texture from the palette):

And this is what my program looks like - as you can see: No texture!

Find below the complete source code of the program AND the complete .x file:

namespace WindowsGame1 {
/// <summary>
/// This is the main type for your game
/// </summary>
public class Game1 : Microsoft.Xna.Framework.Game {
    GraphicsDeviceManager graphics;
    SpriteBatch spriteBatch;

    public Game1() {
        graphics = new GraphicsDeviceManager(this);
        Content.RootDirectory = "Content";
    }

    /// <summary>
    /// Allows the game to perform any initialization it needs to before starting to run.
    /// This is where it can query for any required services and load any non-graphic
    /// related content.  Calling base.Initialize will enumerate through any components
    /// and initialize them as well.
    /// </summary>
    protected override void Initialize() {
        // TODO: Add your initialization logic here
        base.Initialize();
    }

    Model newModel;

    /// <summary>
    /// LoadContent will be called once per game and is the place to load
    /// all of your content.
    /// </summary>
    protected override void LoadContent() {
        // Create a new SpriteBatch, which can be used to draw textures.
        spriteBatch = new SpriteBatch(GraphicsDevice);

        // TODO: usse this.Content to load your game content here

        newModel = Content.Load<Model>(@"aau3d");

        foreach (ModelMesh mesh in newModel.Meshes) {

            foreach (ModelMeshPart meshPart in mesh.MeshParts) {

                meshPart.Effect = new BasicEffect(this.GraphicsDevice, null);
            }
        }

    }

    /// <summary>
    /// UnloadContent will be called once per game and is the place to unload
    /// all content.
    /// </summary>
    protected override void UnloadContent() {
        // TODO: Unload any non ContentManager content here
    }

    /// <summary>
    /// Allows the game to run logic such as updating the world,
    /// checking for collisions, gathering input, and playing audio.
    /// </summary>
    /// <param name="gameTime">Provides a snapshot of timing values.</param>
    protected override void Update(GameTime gameTime) {
        // Allows the game to exit
        if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
            this.Exit();

        // TODO: Add your update logic here

        base.Update(gameTime);
    }

    /// <summary>
    /// This is called when the game should draw itself.
    /// </summary>
    /// <param name="gameTime">Provides a snapshot of timing values.</param>
    protected override void Draw(GameTime gameTime) {

        if (newModel != null) {

            GraphicsDevice.Clear(Color.CornflowerBlue);

            Matrix[] transforms = new Matrix[newModel.Bones.Count];
            newModel.CopyAbsoluteBoneTransformsTo(transforms);

            foreach (ModelMesh mesh in newModel.Meshes) {
                foreach (BasicEffect effect in mesh.Effects) {
                    effect.EnableDefaultLighting();
                    effect.TextureEnabled = true;

                    effect.World = transforms[mesh.ParentBone.Index] * Matrix.CreateRotationY(0)
                * Matrix.CreateTranslation(new Vector3(0, 0, 0));
                    effect.View = Matrix.CreateLookAt(new Vector3(200, 1000, 200), Vector3.Zero, Vector3.Up);
                    effect.Projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(45.0f),
                        0.75f, 1.0f, 10000.0f);
                }
                mesh.Draw();
            }
        }

        base.Draw(gameTime);
    }
}

}

This is the model I am using (.x):

xof 0303txt 0032 
// SketchUp 6 -> DirectX (c)2008 edecadoudal, supports: faces, normals and textures 

Material Default_Material{

1.0;1.0;1.0;1.0;;
3.2;
0.000000;0.000000;0.000000;;
0.000000;0.000000;0.000000;;
} 
Material _Groundcover_RiverRock_4inch_{ 
0.568627450980392;0.494117647058824;0.427450980392157;1.0;;
3.2;
0.000000;0.000000;0.000000;;
0.000000;0.000000;0.000000;;
   TextureFilename { "aau3d.xGroundcover_RiverRock_4inch.jpg";   } 
} 
Mesh mesh_0{
 4;
 -81.6535;0.0000;74.8031;,
 -0.0000;0.0000;0.0000;,
 -81.6535;0.0000;0.0000;,
 -0.0000;0.0000;74.8031;;
 2;
 3;0,1,2,
 3;1,0,3;;
  MeshMaterialList {
  2;
  2;
  1,
  1;
  { Default_Material }
  { _Groundcover_RiverRock_4inch_ }
  }
  MeshTextureCoords {
  4;
  -2.1168,-3.4022;
  1.0000,-0.0000;
  1.0000,-3.4022;
  -2.1168,-0.0000;;
  }
  MeshNormals {
  4;
    0.0000;1.0000;-0.0000;
0.0000;1.0000;-0.0000;
0.0000;1.0000;-0.0000;
0.0000;1.0000;-0.0000;;
  2;
  3;0,1,2;
  3;1,0,3;;
  }
 }