Avast turn off shield

Sometimes Avast turn off shield- there’s a info that something turn it off, but system is not infected, everything is clean. Someone can help?

do you have any other security programs installed?
what AV did you use befor avast?
did you remove it before installing avast?

do you have any other security programs installed?- no
what AV did you use befor avast?- Norton
did you remove it before installing avast?-yes

also I got a windows 8, and when avast is turned off I cant connect to network.
It is possible that firewall turning off avast???

what AV did you use befor avast?- Norton
run Norton removal tool and reboot so that all conflicting files are removed

you find it here Nr #26a http://singularlabs.com/uninstallers/security-software/

also I got a windows 8, and when avast is turned off I cant connect to network.
do you mean another machine? same thing, you must remove any previous used or preinstalled AV before installing avast and use the vendors removal tool to clear any leftover files

did this solve your problem?

Norton removal tool crashes at end of removing norton components, but maybe it remove something that turning off avast, I’ll post here if avast still turn off .
THX 4 help m8 : )