namespace WindowsApplication1
    {
      public partial class Form1 : Form
      {
        public Form1()
        {
          InitializeComponent();
        }


        private void draw_Click(object sender, EventArgs e)
        {
          tableLayoutPanel1.Controls.Clear();
          string[] results = { "Heads", "Tails" };
          int nCoins = Convert.ToInt32(coins.Value);
          Random random = new Random();
          for(int i = 0; i < nCoins; i++) {
            ComboBox coin = new ComboBox();
            coin.Items.AddRange(results);
            coin.SelectedIndex = random.Next(0, 2);
            tableLayoutPanel1.Controls.Add(coin, 0, i);
          }
       }
    }
 }

coin.DropDownStyle = ComboBoxStyle.DropDownList;

coin.CanFocus = false;

coin.TopLevelControl.Focus();

using System;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            button1.Click += new EventHandler(button1_Click);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            tableLayoutPanel1.Controls.Clear();
            string[] results = { "Heads", "Tails" };
            int nCoins = Convert.ToInt32(coins.Value);
            Random random = new Random();
            for (int i = 0; i < nCoins; i++)
            {
                ComboBox coin = new ComboBox();
                coin.SelectedIndexChanged += new System.EventHandler(this.comboBox1_SelectedIndexChanged);
                coin.Items.AddRange(results);
                coin.SelectedIndex = random.Next(0, 2);
                tableLayoutPanel1.Controls.Add(coin, 0, i);
            }
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            this.ActiveControl = null;
        }

    }
}

public class CustomComboBox : ComboBox
{
    private const int WM_SIZE = 0x0005;

    protected override void WndProc(ref Message m)
    {
        base.WndProc(ref m);

        // A fix for ComboBoxStyle.DropDown mode.
        if (DropDownStyle == ComboBoxStyle.DropDown
            && (m.Msg & WM_SIZE) == WM_SIZE)
        {
            Select(0, 0);
        }
    }
}