Pevent default formatting on numbers when exporting GridView to Excel file

Refer my article

Export GridView To Word Excel PDF CSV Formats in ASP.Net

Here I am exporting to Excel and before exporting I am applying a style TextMode to all cells. So that all cells are treated a string

If i Mod 2 <> 0 Then
               row.Cells(0).Attributes.Add("class", "textmode")
                         row.Cells(1).Attributes.Add("class", "textmode")
                        row.Cells(2).Attributes.Add("class", "textmode")
                       row.Cells(3).Attributes.Add("class", "textmode")
           End If

No since DataSet does not have any styling. You can make use of a hidden GridView for exporting dataset as described here

Export DataSet or DataTable to Word Excel PDF and CSV Formats