I've personally never experienced a blue screen with Poser 5 (Win2K, PIII 800, 512 MB RAM). Some people did, but since the anti-piracy protection got disabled, those reports vanished. Especially from Win2K users, I can't remember a single one (except for yours). I can't imagine what in P5 SR3 could cause a blue screen. You said earlier on that you had applied the Poser 4 memory updater to Poser 5, was that correct? If you'd install this updater, you'd "downdate" a critical low-level Poser component to a 2 years older version. That could potentially cause a blue-screen.