Quote - Okay - just playing with this.

I made a backup of my runtime folder onto my desktop... did a bunch of organizing there, but when I add the (backup) folder back to my Poser library (easy to find), it comes up with nothing - as in, 0 files/folders. What did I do wrong? 

Not sure what to tell you here... except... you did it backward from the way I did it. I made a backup of my runtimes, then edited the existing runtimes. That way I could see the changes inside of Poser as they were being made and  KNEW that what I was doing was working. Just needed to hit the redfresh buttom to see the results.

$.02