You neglected to mention which OS you are using to load PP2012.  If you are using Win7/Win8, then you must install PP2012 with the default placing your Poser Content into a shared folder under Documents.  The pathway for Poser content must point that folder.  There are several threads in the forum which give more thorough explanations.

Now, did the V4 package you d/l'ed contain zip files or exe installers?  If installers, the exe will not recognize Poserpro.exe as the valid app install; you must create a dummy Poser.exe and place it in a folder containing a runtime.  If the bundle contains zip files only, then unzip to a runtime of your choice or create your own.