how to get excel data and convert Xml and save existing Xml

Hi Ani, Please refer below link

Excel to XML Conversion in Visual Studio

http://www.c-sharpcorner.com/UploadFile/097c29/excel-to-xml-conversation-in-visual-studio/

If you want to update a node in XML, the XmlDocument is fine - you needn't use XmlTextWriter.

XmlDocument doc = new XmlDocument();

doc.Load("D:\\build.xml");

XmlNode root = doc.DocumentElement;

XmlNode myNode = root.SelectSingleNode("descendant::books");

myNode.Value = "blabla";

doc.Save("D:\\build.xml");