The quick solution is to ask. I have 3 versions of Poser on my machine, and actually use them all. You can check the registry, but that can give an error on a multple registration, or you could search the drives for "poser.exe", but that's darn time consuming. If you use ernyoka1's idea, tell then up front you can cancel and do a manual search. With most software, checking the registry is the best idea, but with so many people running multiple versions of Poser, I'd do the manual method. Besides, it cuts down on your programming time.