c# File in xml format not opening in xml viewer

Created a .xml file in C# console program using StreamWriter without using any xml write library functions). However, it does not show data in XML viewer - shows fine if opened as a text file. I tried, like I say somewhere on this site, the following -

FileStream fStream = new FileStream (@"c:\new.xml", FileMode.Create)

StreamWriter fWrite = new StreamWriter(fStream, Encoding.UTF8);

fwrite.WriteLine (myLine);

where the first myLine was

Is there a way to make this open like an xml file without having to use the xml lib functions?