display xml item in a form

In fact, there are 10 articles in the XML articles in this web site about LINQ to XML. The XmlSerializer class is also useful; there are 4 artilces anout it including one I wrote. Mahesh's article uses XmlTextReader and there are other possibilities.

It's difficult to answer this question without knowing what the XML file looks like and which items need to be extracted.

However, my second post on this thread (http://www.c-sharpcorner.com/Forums/Thread/115470/struggling-to-find-a-suitbale-way.aspx) shows how to read an XML file using LINQ and assign the various items to properties of custom classes.

It's then just a matter of assigning these properties (suitably converted) to the properties of the controls on the form. 

I am confused; do you need to write XML or read it? Regarless, look at:

XML .NET

If that does not help then please clarify what it is that you need help with.

Check this artice.
Reading and Writing XML in C#

In this article, you can learn how to read an XML file. You can read a node from XML (value or attribute) and once you get the value in string, you can set Text property of a TextBox.