AppArmor security policies completely define what system resources individual applications can access, and with what privileges. A number of default policies are included with AppArmor, and using a combination of advanced static analysis and learning-based tools, AppArmor policies for even very complex applications can be deployed successfully in a matter of hours.
AppArmor is more used for the server system where security is the top priority, in my opinion you don't need it to configure a secure system for home desktop, and it usually causes more problems than advantages so, it's better to disable it for the home used computer but make sure you atleast run a firewall which is more useful.
Open up the terminal Application > Accessories > Terminal and type following command
sudo /etc/init.d/apparmor stop
sudo update-rc.d -f apparmor remove