@Technical and eangulus
I beleive we are still on the topic.
eangulus, have to you tried doing the same thing as you mentioned in your first post, but without using system restore, and then checking if the registry key referrenced so many times in this thread is both there and correct?
Also, yes, I have tried emulating what you described with system restore.. For some reason, after a system restore operation, Avast will correctly produce teh said registry key and all will be good.

@norxh
Note, the differences in VLK PRO, PRO and Home are not that drastic or important.. But, if someone thinks it matters, yes.. I have tried it on all of the 3.... Even a persons machine that I beleive had a VLK version of PRO.

And for the last time

fresh clean install of slipstreamed sp2. I always destroy the entire existing copy of windows before installing again. Upgrading a old install sucks!
@Everyone
The final point is, some may not be having the problem, but others deffinately are. I can easily reproduce the problem on several machines. Said problem being strictly the registry key mentioned does not get produced on all installs and I have to manually add it. Then Avast work 100% great.
BTW, yes I can reproduce it on many machines. All will run anything else flawlessly. Hardware is in ideal working conditions and considerable variety amongst them all.
Finally, all names mentioned above, do not take anything I said personally, I am just getting a little frustrated. If avast setup has/had a nice logging feature I would run it. It may have one already that I am not aware of, but no one has suggested it so is it safe to assume it doesnt?