How do I open an EPUB ebook in ADE ? - Getting Adobe Error

Help...........This is my first time trying to download an ebook to my Computer (Windows 7)

I just got an Adobe ID and downloaded Adobe Digital Edition (ADE) 3.0 as an Icon on my Window's Desktop.   When I open it, all I see are tons of instructions but nothing applies to the problem I'm having.

I downloaded a Library EPUBebook which is an .acsm file  and when I open it, it immediately goes to Adobe XI and  opens with an error. - The Library is closed until Tuesday and I don't even know if they will help.

ERROR says:  "Adobe Reader could not open "......................acsm"  because it is either not a supported file type or because the file has been damaged."

I'm sure the file is not corrupted as someone else had borrowed it just before me.  I deleted and downloaded it again several times... same problem

I've tried to read all the tips with no results.

It says to drag or type it into ADE but when I open ADE all I see are instructions with no place to drag or type to.   I tried reinstalling but it says ADE is already running.

help?