Thanks for trying to help. I do appreciate it.
When you say ‘You won’t need them with AIS’ I’m sorry but I disagree.
Both of those programs are protection against specific types of security risk. For example when was the last time that Avast warned you that a site was trying to install a BHO? It doesn’t.

I have a suspicion that it may be conflicting with my nVidia software. I might be wrong though.

Another possible clue is that when I ‘shutdown’ some icons in the system tray disappear but everything else remains active including the desktop and I can move the cursor about and actually select items but they won’t activate, a window comes up with an error message. Then after about 10 minutes the ‘Saving personal settings’ little window comes up and the machine promptly shuts down.

So it would seem that Avast is not allowing a program to close.