Как определить кодировку текста с кириллицей

Dim put as string="D:\123.txt"
Dim text As New StreamReader(put, System.Text.Encoding.ASCII)
MessageBox(text)

Imports System.Drawing
Imports System.Windows.Forms
Imports System.Management.Automation
 
Namespace CyrillicData
  Friend NotInheritable Class frmMain
    Inherits Form
    Public Sub New()
      InitializeComponent()
    End Sub
 
    Private txtText As TextBox
 
    Private Sub InitializeComponent()
      Me.txtText = New TextBox() With { _
        .Dock = DockStyle.Fill, _
        .Multiline = True _
      }
      Me.ClientSize = New Size(300, 210)
      Me.Controls.Add(Me.txtText)
      Me.FormBorderStyle = FormBorderStyle.FixedSingle
      Me.StartPosition = FormStartPosition.CenterScreen
      Me.Text = "CyrillicData"
      AddHandler Me.Load, AddressOf frmMain_Load
    End Sub
    
    Private Sub frmMain_Load(ByVal sender As Object, ByVal e As EventArgs)
      Using ps As PowerShell = PowerShell.Create()
        ps.AddScript("Get-Content E:\sandbox\cyrillic_test.txt -Raw")
 
        For Each o As PSObject In ps.Invoke()
          txtText.Text = o.ToString()
        Next
      End Using
    End Sub
  End Class
 
  Friend NotInheritable Class Program
    <STAThread> _
    Shared Sub Main()
      Application.EnableVisualStyles()
      Application.Run(New frmMain())
    End Sub
  End Class
End Namespace

Function DetectFileEncoding(fileName As String) As Encoding
 
    Dim buf() As Byte
    ReDim buf(12000-1)
    Dim length As Integer
    Using fstream As FileStream = File.OpenRead(fileName)
        length = fstream.Read(buf, 0, buf.Length)
    End Using
    
    Dim d As New Ude.CharsetDetector()
    d.Feed(buf, 0, length)
    d.DataEnd()
    Return Encoding.GetEncoding(d.Charset)
 
End Function

      Dim client As New System.Net.WebClient()
        '   Download URL
        Dim uri As New Uri("http://cyberforum.ru")
        Dim dbytes As Byte() = client.DownloadData(uri)
        Dim htmlcod As String
 
        '   Кодировка по умолчанию
        htmlcod = System.Text.Encoding.Default.GetString(dbytes)
        '  Далее у меня возникает ошибка
        '  Значение типа Byte() невозможно преобразовать в String
        TextBox1.Text = DetectFileEncoding(dbytes)

Function DetectFileEncoding(fileName As String) As Encoding