HI radiofan12 double click on the avast icon on the desktop or double click on the orange ball in the lower right toolbar. That will take you to the GuI and then click on the tab named additional protection under that click on browser protection and their it lists the browsers you have installed and if the Web Rep plug-in is installed or not click on install next to the browser you wish to install Web Rep and then double click on your browser for the changes to take effect.
If you need help leave more questions
Thanks have a great day