As systems manager (in my spare time and amongst my "proper" duties) of a fair-sized system of networked PCs in an association I have experience with most of the programmes mentioned. We have settled on the corporate version of Computer Associates e-Trust as being the best solution and, for home applications, I think I would second Gurney's suggestion of the e-Trust EZ version (a light version of the commercial application) as being excellent value for money (about $25 last time I looked) and very effective.

Of course I avoid all of these problems at home using a Mac running OS 10.2 (ducks and runs for cover!).

moo