18. User Account Controls $#^ percent!~\!!!.

Vista's new User Account Controls functionality is grounded in a very good idea. For more than 15 years, millions of Windows users have been operating their computers with the doors and windows wide open. Early versions of Windows had no log-in limitation; Windows NT, 2000 and XP have always had log-in-based system privileges, but they're cumbmersome. The trouble has been that using anything other than the default "Administrator" account (or an account with computer-administrator privileges) prevented application installation and many other common activities. While it was possible to configure accounts that had some more advanced privileges, the real-world task of living in such environments was inconvenient at best, and downright annoying and time-consuming at worst.

Microsoft set out to change that in Vista with what it calls User Account Controls (UAC). Given that both Linux and the Mac require users to authenticate their administrator privileges (or, in Linux's case, to log in as root, which requires authentication), this shouldn't be an impossible problem for Microsoft. But somewhere along the way, Microsoft decided to raise the bar even higher.

Vista requires you to create an administrator-class account name as part of installation or first boot, eliminating a major vulnerability. That means, by default, no one is running with the Administrator log-in.