Ed, I looked at my swap file and saw it was set somewhere round 3700 megs. I tried reducing this to 2000, and poser still didn't work. I was just about to write and say 'thanks, but it didn't help', but just for the heck of it I decided to try a setting of 1000 megs. And Pow. Poser 4 is working just fine again. I've still no idea why it suddenly stopped, though. Is it possible for Windows to secretly increase the amount of virtual memory without telling you? (like the way VISA companies slowly increase your credit limit...) Anyway, I'm V V V V V happy. Poser has never died on me before, and I'm shocked at how lost I felt without it! I suppose what I need to do now is to slowly increase the size of the virtual memory to see how high it can get before Poser objects? I mean, a big virtual memory is a good thing normally, isn't it? (genuine question!) And thanks again, to everyone who tried to help. I'm more grateful than I can say. Morph