I just meant that AC uses Adobe's software to allow viewing in the right pane without opening in a new window. I thought maybe I could use a different program in that pane but it didn't work. It would just be simpler if it did but I would never expect such a thing to be put in as it would be less than feasible to allow for any program of your choice to open in that window. Either that or the software I found just does not allow it.
