I have my code as follows :-

Microsoft.Office.Interop.Excel.Application oXL = null;
Microsoft.Office.Interop.Excel.Sheets sheets;
Application excel = new Microsoft.Office.Interop.Excel.Application();


excel.Workbooks.Add(System.Reflection.Missing.Value);

/*
    * Here is the complete detail's about Workbook.Open()
    * 
    *  Excel.Workbooks.Open(String Filename, Object UpdateLinks, Object ReadOnly, Object Format, 
    *  Object Password, Object WriteResPassword, Object IgnoreReadOnlyRecommended, Object Origin,
    *  Object Delimiter, Object Editable, Object Notify, Object Converter, Object AddToMru, Object Local, Object CorruptLoad)
    */

Workbook workbook = excel.Workbooks.Open(
    System.Web.HttpContext.Current.Server.MapPath("~/App_Data/Template.xlsx"),
    Missing.Value, true, Missing.Value, Missing.Value,
    Missing.Value, Missing.Value, Missing.Value,
    Missing.Value, Missing.Value, Missing.Value,
    Missing.Value, Missing.Value, Missing.Value,
    Missing.Value);
sheets = workbook.Worksheets;

Now for the line :-

workbook = excel.Workbooks.Open(
    System.Web.HttpContext.Current.Server.MapPath("~/App_Data/Template.xlsx"),
    Missing.Value, true, Missing.Value, Missing.Value,
    Missing.Value, Missing.Value, Missing.Value,
    Missing.Value, Missing.Value, Missing.Value,
    Missing.Value, Missing.Value, Missing.Value,
    Missing.Value);

It gets executed directly from the visual studio (F5) but when i try to access it with IIS it wont work.
Throws error as follows:-

Microsoft Office Excel cannot access the file ‘c:\inetpub\wwwroot\Timesheet\App_Data\Template.xlsx’. There are several possible reasons:
• The file name or path does not exist.
• The file is being used by another program.
• The workbook you are trying to save has the same name as a currently open workbook.

I have tried the work around as:-

• Folder and the file exist, giving access to the IUSR_### (IIS user) and to the ASPNET user in the folder where the file is.
  • At Component Services(DCOM) given access to appropriate user.

I have already given all permission’s to the folder where the template(.xlsx) exists

Any suggestions??