Visual Basic

Dim desktop_Save As String = Environment.GetFolderPath(Environment.SpecialFolder.Desktop) & "\SqlLocalDB.msi"

Dim wc As Net.HttpWebRequest = DirectCast(Net.HttpWebRequest.Create(url), Net.HttpWebRequest)
        wc.AllowAutoRedirect = True

Dim resp = Await (New TaskFactory(Of Net.WebResponse)).StartNew(AddressOf wc.GetResponse)
p.Value = 0
p.Maximum = CInt(resp.ContentLength)
Dim rqs = resp.GetResponseStream

Dim fs As New FileStream(desktop_Save, FileMode.Create) '// I should move this before write

Dim bufsize As Integer = 1 << 16
Dim buffer(bufsize) As Byte
Dim got As Integer = 0
Dim total As Integer = 0

Do
   got = Await (New TaskFactory(Of Integer)).FromAsync _
   (AddressOf rqs.BeginRead, AddressOf rqs.EndRead, buffer, 0, bufsize, Nothing)
   total += got

   Dim m_Bytes As String = _
   "Downloading " & (Convert.ToDouble(total) / 1048576).ToString("0.00") & _
   " MB" & "  /  " & (Convert.ToDouble(p.Maximum) / 1024 \ 1024).ToString("0.00") & " MB"

   l.Text = m_Bytes
   p.Increment(got)

Loop Until got = 0

fs.Write(buffer, 0, bufsize) '// I get a incomplete file, 114 megs instead of correct 43
fs.Close()

rqs.Close()
resp.Close()

credDialog = New dialog_credentials(True)
credDialog.TopLevel = True // Can't be top level and ? 
credDialog.MdiParent = Me  // generates the error below
credDialog.StartPosition = FormStartPosition.Manual
credDialog.Left = (Me.Width - credDialog.Width) / 2
credDialog.Top = (Me.Height - credDialog.Height) / 2 - 100

If (credDialog.ShowDialog(Me) = DialogResult.OK) Then // Windows Form Error