If it doesn't show up in PP or DS, it's probably in the wrong folder.  If it's a product from DAZ 3D in an installer, install to the folder CONTAINING the Runtime folder, e.g. DocumentsDAZ 3DMy Library.  If it's a .zip, merge the Runtime folder with the one in your content folder; if the .zip has a Content or My Library folder, merge what's UNDER that folder with the folders UNDER your content folder.

 

If you load a .pz2 in DS you can save it as a Pose Preset, Material Preset, or Character Preset.  You should save it in a DAZ Studio Format content folder (i.e. NOT under Runtime).  If you want it to be in the Runtime folder with your .pz2 file it needs to have the exact same filename and be in the same folder as the .pz2 file.  DS will display the .pz2 with a scroll symbol in the upper left to indicate that it will load the DAZ Studio preset instead of the .pz2.