I am running only AVG at present. Windows defender runs by itself, but I have never seen it actually do anything in Vista, so I let it be. I have, after the problem started, tried others but uninstalled them. I used that live scan or whatever it is Microsoft has, but without an active antivirus it was useless-it spotted things but could not remove them on its own. I bought this laptop the day that Vista came out and, like a stubborn pet I have grown accustomed, even fond of it. But I bought it to test out Vista and have put this thing through the ringer (wringer?). I have reinstalled it about 7 times, not particularly interested in doing it again if I do not have to.