first go to toolbar
it is in office 10
>more commands->show all commands ->speak selected text -> add this
now select Ur whole text and press speak toolbar
in older ms word
Click on the View option at the top of your Word document. Open the Toolbars option.
Click on Speech. This option should be located at the bottom of the Toolbars section.
Once the Speech box has opened, click on Speak Selection icon at the top of the Speech box.