How to use Narrator in Windows Vista?

Please refer to the following contents
  

Narrator is a synthesized text-to-speech tool that can read aloud most of what the screen displays.

1.Click the Start button, and click Control Panel.

2.Click Ease of Access.

3.Click Ease of Access Center.

4.Click Start Narrator.

The Microsoft Narrator screen appears and starts audio reading.

      To choose the text Narrator always reads in the “Microsoft Narrator” menu.
•Echo User’s Keystrokes
   to hear what you type
•Announce System Messages
   to hear background events such as notifications
•Announce Scroll Notification
 to hear an announcement when the screen scrolls