system
9
Hi dreaming, welcome to the forum 
This should really be in a topic of it’s own, but…
Open avast → Additional Protection’ tab → ‘Webrep’ tab → Click ‘uninstall’ on the browsers you have it installed in.
EDIT: If you want it permantly uninstalled, you can also do it through programs and features:
Control Panel → uninstall a program → avast → choose change → un check the webrep option.
Scott