You have to set up a timer like this.
Googling produced many results "close windows form using timer"
using Timer = System.Windows.Forms.Timer;
private void Form1_Load(object sender, EventArgs e)
{
Timer MyTimer = new Timer();
MyTimer.Interval = (1 * 60 * 1000);
MyTimer.Tick += new EventHandler(timer1_Tick);
MyTimer.Start();
}
private void timer1_Tick(object sender, EventArgs e)
{
label9.Text = (int.Parse(label9.Text) - 1).ToString();
if (int.Parse(label9.Text) == 0)
this.Close();
}
}
}