Sorry Simon, and thanks Hook.
Well, I didn't know that it doesn't work on "Home Edition". I change my system from time to time, between Home and Professional. I was lucky today to have it Professional, which made it work for me.
But, in fact, it's really an interesting area to visit. It's much more simple than the registry to modify and to understand. Maybe even it's much less risky, as you know here what you're doing and why and how.