Where obtain 2008 Dataset Designer?

I would like to know where the dataset designer is obtained for a C#.net 2008 application I need to work on.

Is this part of the initial install for visual studio.net 2008. If so, what part of the initial install will I find the dataset designer?

Is this a plugin that needs to be downloaded? if so, what URL do I need to use to obtain the plugin?

Basically my company just purchased a new licesnse for me to use Visual Studio.net 2008 professional edition. I need to modify some tables that are behind a current application. When I use this new version of Visual studio.net 2008, I can not find an .xsd file that I can open with a desinger to see all the tables that are used in this application. I know there is a designer with this application, since I can not step through this code. The 'designer' generated the code I can not step through.