Use XML, Deskripsi tiap row Menyusul Source : Mbah google ( authornya lupa ) di modifikasi sedikit.

Export to Excel From DataGridView VB.Net, XML

 Public Shared Sub _ExporttoExcel(ByVal _DataGridView As DataGridView, ByVal _Form As Form)
        Dim Excel As New IO.StreamWriter(Application.StartupPath & "\Export.xls", False)
        Dim _Tmp As String = _Form.Text
        Dim _totalRow As Integer = 0
        Excel.WriteLine("<?xml version=""1.0""?>")
        Excel.WriteLine("<?mso-application progid=""Excel.Sheet""?>")
        Excel.WriteLine("<ss:Workbook xmlns:ss=""urn:schemas-microsoft-com:office:spreadsheet"">")
        Excel.WriteLine("    <ss:Styles>")
        Excel.WriteLine("        <ss:Style ss:ID=""1"">")
        Excel.WriteLine("           <ss:Font ss:Bold=""0""/>")
        Excel.WriteLine("        </ss:Style>")
        Excel.WriteLine("    </ss:Styles>")
        Excel.WriteLine("    <ss:Worksheet ss:Name=""Export"">")
        Excel.WriteLine("        <ss:Table>")

        With _DataGridView
            _totalRow = .Rows.Count
            For z As Integer = 0 To .Columns.Count - 1
                Excel.WriteLine("            <ss:Column ss:Width=""{0}""/>", .Columns.Item(z).Width)
            Next

            Excel.WriteLine("            <ss:Row ss:StyleID=""1"">")
            For i As Integer = 0 To .Columns.Count - 1
                Excel.WriteLine("                <ss:Cell>")
                Excel.WriteLine(String.Format("<ss:Data ss:Type=""String"">{0}</ss:Data>", .Columns(i).Name))

                Excel.WriteLine("                </ss:Cell>")
            Next
            Excel.WriteLine("            </ss:Row>")

            For x = 0 To .Rows.Count - 1
                _Form.Text = _Tmp & " Export to Excel ( " & x & " / " & _totalRow & ")"
                Excel.WriteLine("            <ss:Row ss:StyleID=""1"">")
                For y = 0 To .Columns.Count - 1
                    Excel.WriteLine("                <ss:Cell>")
                    Excel.WriteLine(String.Format("<ss:Data ss:Type=""String"">{0}</ss:Data>", .Rows(x).Cells(y).Value))
                    Excel.WriteLine("                </ss:Cell>")
                Next
                Excel.WriteLine("            </ss:Row>")
            Next
        End With
        Excel.WriteLine("        </ss:Table>")
        Excel.WriteLine("    </ss:Worksheet>")
        Excel.WriteLine("</ss:Workbook>")
        Excel.Close()
        Dim FileNameTmp As String = "c:\Export" & Format(Now, "ddMMyyyyhhmmss") & ".xls"
        System.IO.File.Copy(Application.StartupPath & "\Export.xls", FileNameTmp)
        _Form.Text = _Form.Text & " Selesai, Proses Buka File"
        Threading.Thread.Sleep(100)
        System.Diagnostics.Process.Start(FileNameTmp)
        _Form.Text = _Tmp
    End Sub