Try something like this:
VB Code:
  1. Dim fs As IO.FileStream = New IO.FileStream(filename, IO.FileMode.Open)'open file
  2.         Dim br As New IO.BinaryReader(fs)'read as binary
  3.         Dim b() As Byte = br.ReadBytes(fs.Length)'now the contents are in a byte array
  4.         Dim str As String = System.Text.Encoding.ASCII.GetString(b)'convert byte array to string
  5.         br.Close()'close file
  6.         fs.Close()