Take a look at this article:
Update Checker.
I hope, this is exactly that what you need:
This XML file manages the updates:
="1.0"="UTF-8"="yes"
<myCoolApp>
<currentVersion>
<major>9</major>
<minor>1</minor>
<build>5</build>
</currentVersion>
<path>http://TestApp.exe</path>
</myCoolApp>
The main funtion Check4Update() reads the XML file and parse it:
XmlDocument oDom = new XmlDocument();
oDom.Load(_sXmlConfig);
string str = oDom.SelectSingleNode("//currentVersion/major").InnerText;
Int32.TryParse(str, out _nMajor);
str = oDom.SelectSingleNode("//currentVersion/minor").InnerText;
Int32.TryParse(str, out _nMinor);
str = oDom.SelectSingleNode("//currentVersion/build").InnerText;
Int32.TryParse(str, out _nBuild);
_sNewVersionPath = oDom.SelectSingleNode("//path").InnerText;