Well, I know the validation is a new thing from microsoft, as new as this month maybe. The one I encountered told me that I didn't have to have it, but if I didn't agree to the validation then I couldn't download microsoft stuff. Since my software is licensed anyway it didn't matter.. except I saw a notation that once you allowed it you could never uninstall it. It is their drive to combat piracy of their software.
I had norton and uninstalled it except for that NAV part which is still listed as being there. I just ignore it, since most of Norton is long gone. Kaspersky doesn't seem to mind it being there.
I know this doesn't answer your logon/off question... but at least you know why you never saw the other stuff before. It was my impression that you should have been able to agree to take that or not, unless you have automatic download and install. I don't trust MS enough to give them automatic privileges. I still have a functional logon/off, so you should be able to get that running again even if you do have that validation.
I know that they kind of have us over a barrel with all their patching and whatnot, and I usually end up taking their download. But I like to read about them first. I have declined one or two.
Have you tried re-installing logons?