How to move a form to center position

Just set the form's StartPosition property to CenterScreen.

using System.Windows.Forms; 
using System; 
using System.Drawing; 
namespace WindowsFormsApplication
{ 
 public partial class Form : Form 
 { 
 public Form() 
 { 
 InitializeComponent(); 
 this.StartPosition = FormStartPosition.CenterScreen; 
 } 

 private void Center(Form form) 
 { 
 form.Location = new Point(
 (Screen.PrimaryScreen.Bounds.Size.Width / 2) - (form.Size.Width / 2), 
 (Screen.PrimaryScreen.Bounds.Size.Height / 2) - (form.Size.Height / 2)); 
 } 

 private void button_Click(object sender, EventArgs e) 
 { 
 Center(this); 
 } 
 } 
}

Reference : Move a form to center position