threat defense

Now the technology really is too developed, I think if I can like a friend that knows so much knowledge, I will be able to Joseph about. Recently my computer does not know how, always very card, I do not how to love it, then I want to make friends with a look, after seeing him, just give me a threat defense installed, he said that with this threat defense, my computer it does not have some of the destruction of the virus, so my computer is safe, but also can help me clean up some bad rubbish, heard friends say this, I think the threat defense is really good, but I threat defense on the knowledge of the solution too little. My friends say I do not understand, I think I should learn some more knowledge more good.