Principal.cs

using System;
using System.Windows.Forms;

namespace R714PosicionFijaFormulario
{
    public partial class Principal : Form
    {
        public Principal()
        {
            InitializeComponent();
        }

        private void btnFijarFormularioForma1_Click(object sender, EventArgs e)
        {
            Form frmFormularioFijo = new Form();
            frmFormularioFijo.FormBorderStyle = FormBorderStyle.None;
            frmFormularioFijo.Show();
        }

        private void btnFijarFormularioForma2_Click(object sender, EventArgs e)
        {
            Form frmFormularioFijo = new Form();
            frmFormularioFijo.ControlBox = false;
            frmFormularioFijo.MaximizeBox = false;
            frmFormularioFijo.MinimizeBox = false;
            frmFormularioFijo.Text = String.Empty;
            frmFormularioFijo.FormBorderStyle = FormBorderStyle.FixedSingle;
            frmFormularioFijo.Show();
        }
    }
}