I do not understand why people complain about UAC being a Vista only issue. You have to go through the same type of dialog with Mac OS X (At least the version of Tiger which I used before) and in Linux. You have to "authenticate" or run certain programs using "sudo" which is essentially the same thing as the overlay box asking your permission in Vista. Why all the hate for the last operating system to prevent escalated privileges from being granted automatically? Personally I prefer that Vista is letting me know that something is trying to gain escalated privileges so I can be sure I'm not letting malware infect my computer.