can i install avast now with KB3000850 windows update?
I think you can. Are you on Windows 7 or Windows 8? I am on Window 7 SP1. Before you install avast uninstall your current antivirus software and run it’s uninstall/removal utility in safe mode. After you have done that install avast and once avast is installed it will do a quick scan and after that do a manual reboot of your computer and register your copy of avast. Enjoy.
Any questions you may have we will help you.
im using windows 8.1.
I already uninstalled kb3000850 and installed avast.
There’s nothing wrong with my system right now but im still observing.
thanks for the reply anyway. 
Your welcome :). Just curious did you try to install that update and see what will happen? I have heard that one of the update I am not sure if it’s that one or not and it affected Windows 8.1 OS with Avast.
nope… i didnt try it… 
Yes.
There you have it jamirserasib. You can now install that update. I think it got fixed couple of month ago so it won’t affect your OS and avast.