Do not install this one unless you have time to waste! Lots and lots of people reporting problems and I've wasted hours recovering a machine three times from the black screen with mouse cursor curse! Hide it until M$ fixes at least some of the problems. When you do try it make sure that it's the only update you run - i.e. don't let any other updates install at the same time, and reboot the machine a couple of times after you do, before you try doing anything else. This is an "Optional" update related to video and not a security update, so you don't need to install it anyway!