It looks like you already have a possible answer from other posters. I'll
state the obvious that when the UAC is turned off and more workarounds are in
place to prevents prompts, you system is more vulnerable to attack.
Just like everything thinks they are a good driver,

everyone thinks they
are "careful" and won't get malware. However, if the zero day exploits in
Flash and attacks via ads served by third parties in trusted websites and
poisoned DNS aren't enough to scare you, then you have a high opinion of your
third party protections.
I've never had a good explaination of what people do that causes these
prompts and why they are so intrusive. The only time I get them is to run
programs with deep drivers like CoreTemp or Probe2 or backup/image software.
I get a prompt that says Windows needs my permission and I give it. No harm,
no foul. The alternative is Disneyland for all programs and processes.
Just my $.02