On auto Avast will check after Windows starts and once every four hours. You cannot change these settings. I have my definitions files on auto and my programs set to notify when a program update is available. In which case, I usually see a blue Avast window in the bottom right hand corner notifying that a program update is availabe. It does not stay up indefinitely though. I normally see it when Windows start up. Program updates, on average, normally occur about every 4 to 8 weeks.