Почему не сохраняется формат текста из WebBrowser?

_Doc.execCommand("Bold", False, Nothing)

  Dim SaveFileDialog As New SaveFileDialog
        SaveFileDialog.Filter = "HTML файлы|*.html; *.htm"  '  "Текстовые файлы (*.txt)|*.txt|Все файлы (*.*)|*.*"
        If (SaveFileDialog.ShowDialog(Me) = System.Windows.Forms.DialogResult.OK) Then
            Dim FileName As String = SaveFileDialog.FileName
            ' Здесь добавить код для сохранения содержимого формы в файл.
            Dim MSDNpage As String = WebBrowser1.DocumentText
            My.Computer.FileSystem.WriteAllText(SaveFileDialog.FileName, MSDNpage, False)
        End If

Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        
        WebBrowser1.DocumentText = "ggg"
    End Sub
 
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Me.WebBrowser1.Document.ExecCommand("bold", False, True)
        MsgBox(WebBrowser1.DocumentText & vbCrLf & WebBrowser1.Document.Body.InnerHtml)
    End Sub

Dim MSDNpage As String = WebBrowser1.Document.Body.InnerHtml
My.Computer.FileSystem.WriteAllText(SaveFileDialog.FileName, MSDNpage, False)

Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        WebBrowser1.Navigate("D:\1.html")
    End Sub
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        WebBrowser1.Document.ExecCommand("bold", False, True)
        WebBrowser1.Document.ExecCommand("copy", False, True)
        Dim seltxt As String = Clipboard.GetText : Clipboard.Clear()
 
        Dim txtedit As String = Replace(WebBrowser1.DocumentText, seltxt, "<STRONG>" & seltxt & "</STRONG>")
        IO.File.WriteAllText("D:\1.html", txtedit)
    End Sub

    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        WebBrowser1.Navigate("D:\1.html")
    End Sub
    Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        WebBrowser1.Document.ExecCommand("bold", False, True)
        Dim tmptxt As String = Clipboard.GetText
        WebBrowser1.Document.ExecCommand("copy", False, True)
        Dim seltxt As String = Clipboard.GetText : Clipboard.Clear() : Clipboard.SetText(tmptxt)
 
        Dim txtedit As String = Replace(WebBrowser1.DocumentText, seltxt, "<STRONG>" & seltxt & "</STRONG>")
        IO.File.WriteAllText("D:\1.html", txtedit)
    End Sub

   Dim seltxt As String = Clipboard.GetText
        Clipboard.Clear()
        Clipboard.SetText(tmptxt)

   Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        WebBrowser1.Document.ExecCommand("bold", True, True)
        Dim tmptxt As String = WebBrowser1.Document.ActiveElement.InnerText  
        Dim txtedit As String = Replace(WebBrowser1.DocumentText, tmptxt, "<STRONG>" & tmptxt & "</STRONG>")
        IO.File.WriteAllText("D:\2q.html", txtedit, System.Text.Encoding.UTF8)
    End Sub