Lol. It is a little misleading to say "it was my antivirus." The antivirus software is just a co-factor, but most likely not the underlying cause. It reduces the amount of memory available, and thus you get stuttering video, but it is the amount of memory available that is the real cause. As long as you understand this, its all good. I'll keep my fingers crossed for you that you don't get a virus in the meantime.