I can't download Itunes updates through Itunes. I have to go directly to the itunes website

I have tried time and time again to use the Itunes program to get updates from the Itunes website, but if I want to update, I have to come to the website through IE explorer. I get the following notice (See screen shot) and when I click install, it brings me to the UAC (User Account Control) and asks for permission to install. I click yes, and it just brings me back to what you see in the screen shot. I've turned off the UAC, and now, it just won't do anything, once I click install. Any ideas ?