Question

How would it be possible to spawn a new form e.g. Form2 from Form1, but make sure Form2 is adjacent to Form1, for example:

Answer 1

Try handling the LocationChanged event of the main form.

Simple demo:

public partial class Form1 : Form {
  Form2 f2;

  public Form1() {
    InitializeComponent();
    this.LocationChanged += new EventHandler(Form1_LocationChanged);
  }

  private void button1_Click(object sender, EventArgs e) {
    f2 = new Form2();
    f2.StartPosition = FormStartPosition.Manual;
    f2.Location = new Point(this.Right, this.Top);
    f2.Height = this.Height;
    f2.Show();
  }

  void Form1_LocationChanged(object sender, EventArgs e) {
    if (f2 != null)
      f2.Location = new Point(this.Right, this.Top);
  }
}