Running tasks as administrator and user account control
When working with Windows 8, it might be necessary to impersonate
another user, usually the administrator account, to perform a task.
Prior to user account control (UAC), many applications relied on
administrative credentials and privileges to perform their tasks. Doing
this enabled the applications to function unchecked and, if
compromised, cause potential problems across a computer or even
throughout a networked environment. UAC requires the applications to
function without elevated control, unless it is specifically granted by
the user who is signed in.
User account control was created to ensure that most user accounts
cannot perform actions that could damage the operating system. By
default, UAC is enabled and set to a moderate level, which alerts you
when system-changing events happen. For example, when you try to
perform an action that exceeds the privilege level of your user
account, UAC presents a sign-in dialog box asking for credentials with
enough privilege to complete the task. Figure 1 shows an example of the UAC prompt dialog box.
The goal of UAC is to prevent users from allowing everything to run
with the highest privilege possible without at least being alerted to
the actions. Actions that require additional elevation will prompt the
signed-in user to provide credentials with more access rights than the
current user account or alert the user of actions being taken. When UAC
is turned on, very few applications can perform actions without the
knowledge of the person using the computer.
To determine and modify the level of universal account control on a computer, complete the following steps:
-
On the Start screen, type UAC and press Enter.
-
Select Settings from the search results.
-
Select Change User Account Control Settings.
Figure 2 shows the UAC Settings dialog box.
-
Choose one of the following options:
If you choose the option of never being notified, you have effectively disabled UAC.
-
When you have chosen the settings that will work best for your computer, tap or click OK.
-
Restart your computer for the changes to UAC settings to take effect.
The option to dim the desktop as part of UAC helps make sure whoever
is using the computer is aware of the prompt for changes. Many times
with a dialog box, the first option selected or highlighted is chosen
by using the Enter key, and the message presented is not reviewed.
Changing the brightness of the desktop along with the dialog box will
grab the user’s attention. In addition, because a malicious application
could produce a dialog box that looks identical to a Microsoft dialog
box, the desktop is dimmed to ensure that you notice when something is
modifying your computer.
