My pc is being attacked, what do i do in this situation?

my search engines are down (all of them) and I can't look up a cure on the internet. my system restore says something about being "blocked by a group" so my last resort option is gone. this AVG security thing isn't doing it's job, and I have no idea how to combat this virus on my computer. I know that somewhere on my system, something is sabotaging it from the inside, or else AVG would have done something about it. so what course of action can I take so I can get rid of this virus and not have to delete everything from my hard drive?