Hi Kayma,
I'm in the same boat, historically :), ditched Poser a long time ago.
Unless you can see from the dates on the folders that it is old Poser related, so they can simply be deleted, I would clearly recommend the procedure below.
If I were you, I would start by forgetting the old Runtime, delete it, and simply create a new Content folder. When you install new things, drag and drop directly from the ZIP folder to Content - most of them
things will work in DS via this method.
Content includes e.g. Aniblocks, Camera Presets, Characters, data, Environments, Figures, Light presets, people, props, Runtime, etc.
Hope some of it makes sense.