User Account Control (UAC), a technology introduced in Vista, is to prevent an application or process making changes to your computer without your explicit consent. Minasi's book, Administering Windows Vista Security: The Big Surprises, listed out the notorious 9 blocked by UAC. For IT professionals, this list deserves a serious review. Imagine if UAC is not in place, what can happen on a computer.

Source

·         Mark Minasi, Administering Windows Vista Security: The Big Surprises