Turning Narrator OFF in Windows Vista

Please follow the below methods:

Method 1:

1) Open Control Panel.
2) Select Ease of Access.
3) Select Ease of Access Center.
4) Select "Use the computer without a display"
5) Remove the check mark from "Turn On Narrator."

Method 2:

1) Click on Start button. (It is called as Pearl in Windows Vista that contains 4 colored flag. It is located in the same position as you had Start button in Windows XP)
2) Click on “Run” and type “msconfig” without quotes and hit enter.
3) You will be displayed with a window named “System Configuration Utility”.
4) There you can find tabs like: General, SYSTEM.INI, WIN.INI, BOOT.INI, Services and Startup.
5) There you should see an entry for Narrator, uncheck the check box for Narrator and hit “Ok” button.
6) Restart your computer.
7) When you do, a notice will pop up stating that you are using a troubleshooting tool, click "dont show me this again" and it will not pop up anymore.

Also please visit:

Article Title: Windows Vista Accessibility Tutorials
http://www.microsoft.com/enable/training/windowsvista/