display images in gridview from imagepath stored in database in windows form

The problem is that you combine wrong path.

you should use:

imgPath= Path.Combine(Application.StartupPath, row1.Cells[3].Value.ToString());

instead of:

imgPath= (Application.StartupPath + row1.Cells[3].Value.ToString());

full code:

foreach (DataGridViewRow row1 in dgvDisplayTiles.Rows)
{
    string imgPath;
    imgPath= Path.Combine(Application.StartupPath, row1.Cells[3].Value.ToString());
    Image imageFile = Image.FromFile(imgPath);
    if (imgPath != null)
    {
        //img.Image=imgPath;
        row1.Cells[3].Value = imageFile;
    }
    else
    {
        MessageBox.Show("Invalid Path");
    }
}

Update#2 :

You can create dynamic columns like this:

For the easy understanding, i create an Employee class and add some dummy data and bind it with the DataGridView

public class Employee
{
    public string id { get; set; }
    public string name { get; set; }
    public string imagePath { get; set; }
}


private void bindGrid()
{
    List<Employee> employees = new List<Employee>();
    employees.Add(new Employee() {  id = "1",name = "joseph", imagePath = "abc.png" });
    employees.Add(new Employee() {  id = "2", name = "Mac", imagePath = "capture2.png" });
    this.dataGridView1.DataSource = employees;

    DataGridViewImageColumn column = new DataGridViewImageColumn();
    column.Name = "imgColumn1";
    column.HeaderText = "Image";
    this.dataGridView1.Columns.Add(column);
    this.dataGridView1.Refresh();

    foreach (DataGridViewRow row1 in dataGridView1.Rows)
    {
        string imgPath;
        imgPath = Path.Combine(Application.StartupPath, row1.Cells[2].Value.ToString());
        Image imageFile = Image.FromFile(imgPath);

        if (imgPath != null)
        {
            row1.Cells[3].Value = imageFile;
        }
        else
        {
            MessageBox.Show("Invalid Path");
        }
    }
}