[blauesau]

So:

        Try
            Dim myStream As New IO.FileStream(sfd.FileName, IO.FileMode.Create)
            Dim myWriter As New IO.StreamWriter(myStream)
            myWriter.Write(txtFeld.Text)
            myWriter.Close()
            myStream.Close()
        Catch
            MessageBox.Show("Fehler beim Speichern der Datei...", "Fehler", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End Try