I am going to show two ways of Excel Sheet Update using C#. Oneway is Where MS Excel got installed on the Server. Steps to Update Excel File: 1) Get the File Name on the Server. 2) Create _Application calss Instance 3) Create _WorkBook calss Instace for _Application 4) Get the available Sheets for _WorkBook Object 5) Update Excel Sheet Columns with Desired Values. 6) Save the Workbook and Quit Application Add the following Referece to the Program: using Microsoft.Office.Interop.Excel; /// /// Takes Newly Generated ECR No and Updated ECR Form with ECR No, Description /// Need Excel Installed On Production Server using UpdateECRForm() method /// /// protected void UpdateECRForm( int _ECRNo) { string xlsFileName = Server.MapPath( ConfigurationManager .AppSettings[ "NewECRFormName" ].ToString() + _ECRNo + ".xlsx" ); _Application xl = new ApplicationClass (); _Workbook wb = xl.Workbooks.Open(xlsFileName, 0, false , 5, Missing .Value, Missing .Value, false , M...