There are to achieve that, but it would mean changing your account to a "Power" administrator account. The one you are using by default is only a local, or Lan, Administrator, unlike what you were more used to in XP.But the UAC is not , in itself, any form of virus or attack repeller. It is merely a warning that such an event may be trying to take place. In view of the ease with which it can be bypassed, it is not of a great deal of value when "misused"(?).
To find ways to turn off the denial message would, therefore, render it totally impotent, so it then, might as well be disabled.
The majority of hackers in the world, always regard MS as a prime target. For this reason, speaking personally, on first installation I usually turn off any Microsoft defenses that exist. This would include items like the Security service and windows defender. I make sure I have good third party anti virus and spyware control.
This is a controversial subject, as you would realise if you browse on the web. Practise is better than pundit oration, and the fact is that I have rarely experienced any serious attack, either with Vista or any legacy OS's