Is Isolated Storage Always Necessary?

I see alot of examples on how to write data from an app to a file then put it in isolated storage. I do not want to write any data to my xml file, I just simply want to save it into isolated storage then query it later.

A few simple questions

• Someone have code on how to put an existing xml file into isolated storage. Also since I am not writing to this file, do I need isolated storage still? Can I just add the xml to my project and use Linq to xml to open it query it and close it on a button click?

• I wanna query the xml through my application in the background. I see alot of examples on serializing, do I need to do this? Can I just open the xml file and use linq to xml to query the data?

Can I just do this, set bbxml.xml to Content and forget about isolated storage and just do this?

 using (XmlReader reader = XmlReader.Create("bbxml.xml"))
        {
            XDocument xml = XDocument.Load(reader);
            //query xml....
}