C#

XmlDocument document = new XmlDocument();

// Create the root Account element.
XmlElement root = document.CreateElement("Account");
// Add attributes to the element
root.SetAttribute("SomeAttribute", "42");
// Add the element to the document's tree.
document.AppendChild(root);

// Create the child elements
XmlElement child = document.CreateElement("User1");
// Add the child to the root element
root.AppendChild(child);

// Create a grandchild
XmlELement grandchild = document.CreateElement("AccountSetting");
child.AppendChild(grandchild);

//etc, etc...

//Finally you could save the document to file:
document.Save(pathToMyXmlFile);