Its a little out of date but this tutorial shows you how to get started using the System.speech class
It sounds like what you are doing now is trying to use the class directly. The first step is to make an instance of the SpeechSynthesizer or SpeechRecognizer class with which you can perform the System.speech actions.
You need to add a reference to the System.Speech assembly, then you are free to use speech like so:
using System.Speech; // <-- sounds like what you are using, not necessary for this example
using System.Speech.Recognition; // <--- you need this
static void Main(string args)
using (SpeechRecognizer recognizer = new SpeechRecognizer())
// do something
Just in case, here is the reference I am using (via project.References.Add Reference...):
It is not necessary to use the Browse function. I'm assuming you are not using COM too.