Facing Problem in kirupa 's tutorial - Help needed

With reference wot the tutorial -Creating a Simple Text to Speech App
(http://www.kirupa.com/blend_wpf/create_text_to_speech_pg1.htm)

I created the application as the tutorial said but i am getting the error as shown in the Image

And when i right click on the speechsynthesizer thing i don’t get and Visual studios option. i get Notepads option. why is it so?

and 2nd thing what i wanted to ask is - Can i create this application for Web browser using Silverlight ?
I tried it but when i user the reference it says that the assemblies is for .NET not silverlight

3rd problem - when i add a reference i dont get the option as

but i get them as a OPEN dialogue box in Blend .