Circle Form

private void Form1_Load(object sender, EventArgs e)
{
    this.Height = 350;
    this.Width = 350;
    //Creating circle path
    System.Drawing.Drawing2D.GraphicsPath path = new System.Drawing.Drawing2D.GraphicsPath();
    path.AddEllipse(0, 0, 300, 300);
    //Creating the region from the circle path
    this.Region = new Region(path);
    this.Show();
}