How to detect IIS version using C#

Request.ServerVariables["SERVER_SOFTWARE"];

FileVersionInfo verinfo = FileVersionInfo.GetVersionInfo(System.Environment.SystemDirectory + @"inetsrvinetinfo.exe");

//Tip... look at verinfo.MajorVersion.

public Version GetIisVersion()
{
using (RegistryKey componentsKey =
Registry.LocalMachine.OpenSubKey(@"SoftwareMicrosoftInetStp", false))
{
if (componentsKey != null)
{
int majorVersion = (int)componentsKey.GetValue("MajorVersion", -1);
int minorVersion = (int)componentsKey.GetValue("MinorVersion", -1);
if (majorVersion != -1 && minorVersion != -1)
{
return new Version(majorVersion, minorVersion);
}
}
return new Version(0, 0);
}
}