Convert Report In to Word in ASP.Net

 ADD  THIS NAMESPACE's
using System.Text;
using System.IO;
 In a Page we will taken a Button,and Give the Button Name or ID btnExport
This Button Click Event We Write This Code 
C# Code
protected void btnExport_Click(object sender, EventArgs e)
    {
        try
        {
lblReport means here all the data are retrive and store in this LBLreport
            if (lblReport.Text.ToString().Trim() != "")
            {
                StringBuilder s2 = new StringBuilder();
                s2.Append("<table>");
                s2.Append("<tr>");
                s2.Append("<td align='center' colspan='4'>");
                s2.Append("<b>Student Details Report</b>");
                s2.Append("</td>");
                s2.Append("</tr>");
                s2.Append("</table>");
               
              this.ExportToExcel(s2.ToString().Trim()+lblReport.Text.ToString());
            }
            else
            {
                Response.Write("<script language='javascript'>alert('No data exist to export');</script>");
            }
        }
        catch (Exception ex)
        {
            string msg = ex.Message;
        }
    }
// In your Solution Explorer you add a Folder which Name is Exported_Files //
    private void ExportToExcel(string dataToExport)
    {
        try
        {
            string filepath = Server.MapPath("Exported_Files/" + DateTime.Now.ToString("dd-MM-yyyy hh-mm-ss") + ".xls");
            FileStream fs = new FileStream(filepath, FileMode.OpenOrCreate, FileAccess.Write);
            StreamWriter sw = new StreamWriter(fs);
            sw.WriteLine(dataToExport.ToString().Trim());
            sw.Close();
            fs.Close();
            Response.ClearContent();
            Response.ContentType = "application/vnd.ms-excel";
            Response.AddHeader("content-disposition", "attachment;filename=" + filepath);
            Response.WriteFile(filepath);
            Response.End();
        }
        catch (Exception ex)
        {
            string msg = ex.Message;
        }
    }