another alternative is this Excel C# / VB.NET
component that has limited free version that can be used in commercial applications and unlimited professional version.
Here is an Excel VB.NET
code how to export DataSet to Excel
Dim ef = New ExcelFile()
For Each dataTable As DataTable In dataSet.Tables
ef.Worksheets.Add(dataTable.TableName).InsertDataTable(dataTable, 0, 0, True)
ef.SaveXls(dataSet.DataSetName & ".xls")