I second foxit reader. It’s the best PDF viewer available, and it uses so much less memory & disk space than acrobat. Enjoy your Adobe Freedom.

instead of using the adobe pdf reader use this one

just download and install and open the file you were trying to open.

its faster,smaller and simpler to use

enjoy!

Word has associated its self to the .pdf file. Here is your fix.
Right click on the file and select properties
Click the change button where it says to open with
Choose the adobe reader and press ok and apply.
This should take care of it so long as you have adobe reader installed.