http://msdn2.microsoft.com/de-de/library/system.windows.forms.picturebox.imagel_
  ocation(VS.80).aspx

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles MyBase.Load
        PictureBox1.ImageLocation = "Pfad"
        PictureBox1.Load()
End Sub
 
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
  System.EventArgs) Handles Button1.Click
        Me.Text = PictureBox1.ImageLocation
End Sub