I had avast for a few years and paid for the whole shebang. It worked find for a couple years and I would renew my subscription and update. Then, the last time, it completely messed up my computer; I couldn't even connect to the internet - avast blocked it. I couldn't call avast because I found out it's based in Prague, Czech Republic. There was no American contact. It cost me $300 to set my computer back to rights. Then I found out I couldn't remove avast from my hard-drive - it deliberately blocks attempts to do so. Finally, by doing searches from many, many, many disgruntled "costumers" who also had mucho problems with the service how to do it. My advice, from my experience, get rid of it, if you can.
Gerard