Dim myStream As IO.FileStream
Dim openFileDialog1 As New OpenFileDialog()
openFileDialog1.InitialDirectory = "c:\"
openFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*"
openFileDialog1.FilterIndex = 2
openFileDialog1.RestoreDirectory = True
If openFileDialog1.ShowDialog() = DialogResult.OK Then
  myStream = New IO.FileStream(openFileDialog1.FileName, IO.FileMode.Open)
  If Not (myStream Is Nothing) Then
    Dim Reader As New IO.StreamReader(myStream)
    Do While Reader.Peek > -1
      TextBox4.Text = Reader.ReadLine & vbNewLine
    Loop
    Reader.Close()
    myStream.Close()
  End If
End If