I had the same problem with Win98....could never render anything other than the basics. I got XP a couple of months ago and have never had a freeze with it. I can add everything I want to the picture and render over and over again without a problem. Although I've heard the horror stories about XP I'm thankful I have it - just for Poser. It's been a delight to use now! :-) I do, however, check the Microsoft site for patches on a regular basis for XP ;-)