Antivirus

My Mom has had so many viruses on her computers. She recently just had to send her laptop in to be fixed, because the hard-drive was fried from an awful virus. I know she put a new antivirus software on it, but I'm not sure which one. Maybe it was Avira Antivirus. I'll have to ask her. But whatever it was, I hope she has better success with it protecting her pc.