// this.Cursor = new Cursor(this.Cursor.Handle);
// Cursor.Position = new Point(Cursor.Position.X, Cursor.Position.Y);
Cursor.Clip = new Rectangle(this.Location, this.Size);

Screen[] screen = Screen.AllScreens;
this.Cursor = new Cursor(Cursor.Current.Handle);
Cursor.Clip = screen[0].Bounds;