I'm an old customer. Just Installed V4 on Vista. No problems. I deleted V3 before installing V4. I like the addition of Spyinspector. I guess some form of HIPS will be next. If I had not read on this site about the new V4 I wouldn't know it existed. I was under the impression that Automatic Updates included engine updates, but I was wrong. I thank you for a very fine product which has always worked flawlessly for me.