On Windows 10 Version 1607 for x64-based system with latest updates, Avast 17.2.2288 - updated 18 Mar 2017 - the Avast control panel or settings window or whatever you call it will not remain open. It starts to run with the window appearing, then immediately disappears, I assume because it crashes. The Avast Icon disappears for a short time from the "hidden icons" pop-up on the Windows task bar, then reappears.