It's true. There is at least one feature in Windows Vista that was
implemented on time, to spec, and fully functional when Vista was
initially released: User Account Control (UAC).
In a Thursday presentation at RSA 2008 in San Francisco, David Cross, a product unit manager at Microsoft who was part of the team that developed UAC, admitted that Microsoft's strategy with UAC was to irritate users and ISVs in order to get them to change their behavior.
"The reason we put UAC into the platform was to annoy users. I'm serious," said Cross.
Well, we have to admit, Microsoft succeeded. Of course, as Microsoft said, the idea was to get users to change their behavior. For many, what this did was make them search for "how to disable UAC" on Google.