Downloaded Adobe Digital Editions and it is being re-directed to Adobe Acrobat Reader

I have downloaded Adobe Digital Editions 4.5.11 and when I try to recuperate the book I borrowed, it seems to attach it to Adobe Acrobat Reader.  Your support mentions installation problem.  I have installed and uninstalled and installed it numerous times and I still get the same message.  Also, I cannot change the program with which I want to open the file (book).