I just got bit by this damn thing this morning. Everything was fine with the version I had installed and then without any warning, AVAST needs to reboot your computer to update. WTF. Now I have some unwanted, unneeded, crappy white looking UI version that looks like it was puked out of a smart phone.
AVAST, if you are going to force people into new versions without consent, at least update them to the latest version and provide some warning of what the hell is going on while you disregard user settings.
I'm rolling back to a previous disk image and am going to kill the AVAST Emergency Updater.