Poser 4 and 5 both work on XP without any additional problems. Daz also has creature paks for Mike and Vicky to expand their fantasy lives. But there are fantasy creatures available at many sites, including here, 3D Commune, PoserPros, RuntimeDNA, etc. Ask and you will get a ton of recommendations. I like Poser 5. I like Poser 4. I'm not arguing one over the other...just depends on what you want to do. Both have been stable on my computer for the last few months (if you get Poser 5, get the latest patches). Vicky 3 doesn't seem to like Poser 5...I am expecting Mike 3 to be just as stubborn, so I keep both.