using System.Diagnostics;

//In the form load call the method

private void Form1_Load(object sender, EventArgs e)
{
            mOpenFile("Notepad.exe");
}

//Function which will open the executable files

void mOpenFile(string URL)
       {
        Screen scr = Screen.PrimaryScreen; 
        int oldWidth = scr.Bounds.Width; 
        int oldHeight = scr.Bounds.Height; 
        Process proc = new Process(); 
        proc.StartInfo.FileName = URL; // put full path in here 
        proc.StartInfo.WindowStyle =ProcessWindowStyle.Maximized;
        proc.Start(); 

       }