I just go to the directory that holds my CONTENT, and in the same directory I create another CONTENT directory, naming it CONTENT - FREE CHARACTERS or whatever I want to name it. I actually have sparate contents for the following:

CONTENT     default

CONTENT - CLOTHING PURCHASED

CONTENT - CLOTHING FREE

etc, etc

I have 7 contents, each with its own runtime, with no problems. Just make sure to point both DS and the POSER pointers to each directory in Edit>Preferences>Content manager