File Access path denied

Dim format As System.IFormatProvider = New System.Globalization.CultureInfo(CType(Application("StrToDateFormat"), String), True)
      Dim oXL As Excel.Application
      Dim oWB As Excel.Workbook
      Dim oSheet As Excel.Worksheet
      Dim oRng As Excel.Range
      Dim strFileName, strExcelFIle As String
      objDate = System.Convert.ToDateTime(tbToDate.Text, format)

      strExcelFIle = "PlantUtilizationReport " + objDate.ToString("yyMMdd") + ".xls"
      objDate = System.Convert.ToDateTime(tbToDate.Text, format)
      strFileName = MapPath(".") & "\" & strExcelFIle
      Dim TheFile As FileInfo = New FileInfo(strFileName)
      If TheFile.Exists Then
          File.Delete(strFileName)
      End If
      objDate = System.Convert.ToDateTime(tbToDate.Text, format)
      ' Start Excel and get Application object.
      oXL = New Excel.Application
      oWB = oXL.Workbooks.Open("c:\inetpub\wwwroot\LCAccounting\PantOccupancy.xls")
      oSheet = oWB.ActiveSheet

      oSheet.Cells(TodaysDateRow, TodaysDateCol) = tbToDate.Text

      dt = obj.GetTable("SP_FGPlantUtilizationTrnSelForExcel", objDate.ToString("MM/dd/yyyy"))
      Dim RowNo, colNo As Int16
      For Each dr In dt.Rows
          RowNo = dr("RowNo")
          colNo = dr("ColNo")
          oSheet.Cells(RowNo, colNo).Value = dr("UtilizationHours")
          '       oSheet.Cells(RowNo, DailyProductionCol).Value = dr("Qty")

      Next

      dt = obj.GetTable("SP_FGPlantProductionTrnSelForExcel", objDate.ToString("MM/dd/yyyy"))
      For Each dr In dt.Rows
          RowNo = dr("RowNo")
          oSheet.Cells(RowNo, DailyProductionCol).Value = dr("Qty")

      Next

Access is denied.<br />
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.<br />
<br />
Exception Details: System.UnauthorizedAccessException: Access is denied.<br />
<br />
ASP.NET is not authorized to access the requested resource. Consider granting access rights to the resource to the ASP.NET request identity. ASP.NET has a base process identity (typically {MACHINE}\ASPNET on IIS 5 or Network Service on IIS 6) that is used if the application is not impersonating. If the application is impersonating via <identity impersonate="true"/>, the identity will be the anonymous user (typically IUSR_MACHINENAME) or the authenticated request user.<br />
<br />
To grant ASP.NET write access to a file, right-click the file in Explorer, choose "Properties" and select the Security tab. Click "Add" to add the appropriate user or group. Highlight the ASP.NET account, and check the boxes for the desired access.

[UnauthorizedAccessException: Access is denied.]<br />
   BDRegions.Report.lbReport_Click(Object sender, EventArgs e) in C:\Inetpub\wwwroot\LCAccounting\Report.aspx.vb:83<br />
   System.Web.UI.WebControls.LinkButton.OnClick(EventArgs e)<br />
   System.Web.UI.WebControls.LinkButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)<br />
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument)<br />
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)<br />
   System.Web.UI.Page.ProcessRequestMain() +1330<br />