This is informational for anyone who runs into the following issue- There's been a lot of posting on the Internet about slow screen redraw issues with Photoshop CS4, but without many real solutions. Without going into a long and useless reiteration of what's been said already, this was the solution I found when I ran into this with two graphics workstations which had; - Windows XP Pro - Dual core CPUs, 3GB RAM - ATI Radeon HD 2400/256MB video memory. There's an update for CS4 that takes it from version 11.0.0 to 11.0.1. What I found was, the update by itself made no real improvement. A video card upgrade to an Nvidia 9600GT with 1GB video memory by itself made no real improvement. BUT, a video card upgrade AND the CS4 update to 11.0.1 made a world of difference. After both the update and the video card upgrade, the user was able to enlarge a 76MB JPEG of a movie poster to the point where you could make out the shadow of the photographer who took the picture in the eye ball of someone on the poster, and move the picture around with the hand tool with almost 95% fluidity and barely any screen redraw. Good luck! Assume that I already did an Internet search.