Here's how to do it.
1.  Navigate to the desired pdf file.
2. right click the file and go to "open with pull down"
3. Hit the right arrow to select the pulldown menu.
4. If openbook is not on the list, go to the choose program dialog.
5. Navigate to the executible program for openbook and tab to the select button.  I think the file is "ob.exe"  You can check the box to always use the selected program if desired.  I wouldn't though, because their are still pdf files that contain actual text and can be read better in accrobat.
Now press enter on your file, your computer will get openbook ocr the file through the freedom import printer, which is a virtual printer.  Openbook will then start reading the file.
This technique can be used to try any file with any program, so you can test the software with out making the change permanent.