I use Poser since version 2 to Poser pro 2010

I try to never install programs in C:  just OS (Windows 7 64 bits now) , some utilities and some ini file or parameters the softs need to install in a folder like C:UsersNameAppData 

  It is better to have a smaller C  for backup system and install softs and saved data on another drive .All my poser scenes are saved in F : 3d data and some subfolders . Some think  softs need to be installed in c:Program Files or c:Program Files (x86)  It is false. You can install in C if you want but it is not necessary

I have  three versions of Poser and runtines installed on D ,E ,and F without problems with files

Never try to load Poser from external drive except sometime with Poser 7 . I  have tried  to load Poser 7 with this drive connected to my friend system (To show him what is Poser) And Poser load without problem