Poser 5 installs to a different folder than Poser 4 or previous versions. You can keep your existing installations intact (I did this on my own home system). There is no difference between the "upgrade" and "full" versions of Poser 5. People getting the upgrade simply enter a valid Poser 4/Pro Pack/etc. serial number to get the appropriate upgrade price and receive the full box. Once you have P5 intact, simply navigate to your old Poser 4 directory and add your old Runtime folder as a new Library. Guess what: ALL of your existing content will be right there, ready for use! :-) Anthony H. Curious Labs