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Part III:
Securing Windows Vista
Reducing the Need for Administrator Privileges
In earlier versions of Windows, most user accounts are configured as members of the local
administrator’s group to ensure that users can install, update, and run software applications
without conflicts and to perform common system-level tasks. In Windows XP and earlier ver-
sions of Windows, some of the most basic tasks, such as clicking the taskbar clock to view a
calendar, require administrator privileges, and this is why many user accounts are configured
as local administrators. Unfortunately, configuring user accounts as local administrators
makes individual computers and networks vulnerable to malicious software and also makes
maintaining computers more difficult, as users might be able to make unapproved system
changes.
Note
Malicious software programs exploit the system-level privileges provided to the local
administrator. Not only does this allow malicious software to install itself, it also allows mali-
cious software to damage files, change the system configuration, and steal your confidential
data. Some organizations try to combat malicious software by locking down computers and
requiring users to operate in standard user mode. While this can solve some problems with
malicious software, it can also seriously affect productivity, as many applications designed
for Windows XP will not function properly without local administrative rights. Why? Typically,
Windows XP applications use local administrative rights to write to system locations during
normal operations.
Through User Account Control, Windows Vista provides the architecture for running user
accounts with standard user privileges while eliminating the need for using administrator
privileges to perform common tasks. This fundamental shift in computing serves to better
protect computers against malicious software while ensuring that users can perform their
day-to-day tasks.
User Account Control is an architecture that includes a set of infrastructure technologies.
These technologies require all users to run applications and tasks with a standard user
account, limiting administrator-level access to authorized processes. Because of UAC,
computers can be locked down to prevent unauthorized applications from installing and to
stop standard users from making inadvertent changes to system settings.
Defining the Standard User and Administrator User Modes
In Windows Vista, there are two levels of users:
■
Administrator users
Administrator users run applications with an administrator account
and are members of the local Administrators group. When an administrator user starts
an application, her access token and its associated administrator privileges are applied to
the application at run time. This means that an application started by a member of the
local Administrators group runs with all the rights and privileges of a local administrator.
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