If I remember well the installers of V4 and M4 assume the old arrangement with the Poser executable and the Runtime folder in the same master folder. The installer looks for a file 'Poser.exe' and puts the morphs stuff in a location relative to that file.  

Standards for program installation in Windows have changed since for very good reasons. Poser implemented the changes Microsoft called for but the M4 and V4 installers were not updated. (Note neutral tone here) 

To install V4/M4 from the installers you best fool them and add a file named 'Poser.exe' in the folder where the Runtime folder where you want to install the figure sits, and run the installer there. It does not matter what is inside that file. It can be empty. All that matters is that it has a name 'Poser.exe'. You can delete it once you have completed the install. 

Once installed, you have a content Runtime like any other. You can simply activate it from any version of Poser, copy it to new computers or add it to your cloud storage.