The path works for me by the looks of it, i just installed the framework with the defaults.  The logit function is in the code isn't it:

     Public Shared Sub LogIt(ByVal logMessage As String, ByVal w As TextWriter)

        w.Write(ControlChars.CrLf & "Log Entry : ")

        w.WriteLine("{0} {1}", DateTime.Now.ToLongTimeString(), DateTime.Now.ToLongDateString())

        w.WriteLine("  :")

        w.WriteLine("  :{0}", logMessage)

        w.WriteLine("-------------------------------")

        ' Update the underlying file.

        w.Flush()

     End Sub

Excellent article, thanks, i found very usefull.