HOW DO I OPEN THE PDF DOCUMENT?

I have Adobe Digital Editions 4.0 and logged in.  I bought a document from a publisher
(IAPMO.ORG) I downloaded it.  It is a 25mb pdf file.

I found it in my MyDocuments/MyDigitalEditions directory. When I click on the pdf file it opens my browser to this website

http://www.adobe.com/solutions/ebook/digital-editions.html?source=acrofile

HOW DO I OPEN THE DOCUMENT?