bought ebook from simon schuster, downloaded Adobe Digital 3.0, everytime I try to open ebook Adobe reader pops up and say file cannot be opened HELP!!!!!!!!!

I bought an ebook from simon and schuster, it told me I had to download the book to Adobe Digital 3.0.  I downloaded Adobe Digital 3.0 but every time I try to get the book, Adobe reader pops up and says file cannot be opened.  Simon and Schuster has been no help at all, just keep sending the same download instructions@