After this update I had problems with programs and windows components not opening. Click on an icon and I would get an hourglass for a few seconds, and then nothing. Not realizing that the Avast update was the problem, I First did a system restore to when a microsoft critical update had been installed, and this "fixed the problem". In reality, what fixed the problem was going back in time b4 the Avast update. Since I did not suspect Avast as the culprit yet, when I was asked to install the new update again into my restored environment, I clicked yes, and was stunned to find my programs not opening again. This time when I tried System Restore, I got a blue screen. Rebooted, opened in safe mode, started to breathe normally again, uninstalled avast completely, rebooted, got a f***d up screen that froze, started hyperventilating, forced power off manually, rebooted, and... - avast was gone and so were all my problems... Conversely, A classmate has the same update running happily on his machine. Love Avast and normally swear by it, not at it, but something is wrong with this update on certain machines. Not cool.