I am not sure what I did in Reader, but now any pdf I open in Adobe Reader, fully fills my desktop. This is what I am looking for. However the same file opened up in Acrobat does not fully fill the desktop. I've attached the two images to show what I am talking about
see how this pdf opened in Acrobat, although shows the full page, the window is not fully scaled to my desktop as in the other image
Same file opened in Reader
Ok I just figured it out you have to maximize the window by selecting the green plus button in the upper left hand corner. Then quite out of Reader or Acrobat. Any file you open up after that will open with the window maximized.