When I installed an update to CCleaner, I saw the box for installing the "Avast" anti-virus just as I clicked the install option for CCleaner. It is checked by default. Well, it not only installed the Avast anti-virus software, but it disabled the Malwarebytes software I had which runs automatically on start up. I uninstalled the Avast software, but my Malwarebytes software would not come up. I finally checked the Services list, and I fould the Mawarebytes service had been disabled! I really think it takes a lot of nerve to install this anti-virus trial version on my PC, and disable something that I have running. And in a way that takes searching to see what is going on. Just my two cent's worth.