Do you have Reader installed? If so, the following may apply:
Are you using Chrome, Firefox or MS Edge to access the PDF file? These browsers come with their own PDF viewer and it is possible that the Turbo Tax site does not recognize that you have Reader installed.
Only FireFox allows you to turn this internal PDF viewer off. See here for more information:
http://helpx.adobe.com/acrobat/using/display-pdf-browser-acrobat-xi.html
If you don't have Reader installed, you can download it from here: http://get.adobe.com/reader
Karl Heinz Kremer
PDF Acrobatics Without a Net
PDF Software Development, Training and More...
http://www.khkonsulting.com