int x = System.Windows.Forms.Screen.PrimaryScreen.WorkingArea.Size.Width - this.Size.Width - 5;
            int y = System.Windows.Forms.Screen.PrimaryScreen.WorkingArea.Size.Height - this.Size.Height - 5;
            this.SetDesktopLocation(x, y);

注释：
System.Windows.Forms.Screen.PrimaryScreen.WorkingArea.Size.Width;   //当前显示器的宽度
System.Windows.Forms.Screen.PrimaryScreen.WorkingArea.Size.Height; //当前显示器的高度
this.SetDesktopLocation(x,y); //设置窗体打开后在显示器上的坐标

本文转自黄聪博客园博客，原文链接：http://www.cnblogs.com/huangcong/p/4857100.html，如需转载请自行联系原作者