MCSA/MCSE Self-Paced Training Kit (Exam 70-270): Installing ...

1-24 Chapter 1 Introduction to Windows XP Professional
Note If your computer is not part of a domain, the Log On To option is not available.
Windows XP Professional Authentication Process
F01US08.eps
To gain access to a computer running Windows XP Professional or to any resource on
that computer (whether the computer is configured to use the Welcome screen or the
Log On To Windows dialog box), you must provide a user name and possibly a password.
(You will learn more about using passwords effectively in Chapter 7.)
The way Windows XP Professional authenticates a user depends on whether the user
is logging on to a domain or logging on locally to a computer (see Figure 1-8).
1
Logging on
locally
Logs on
3
Access
token
Local
security
database
Figure 1-8 Windows XP Professional grants an access token based on user credentials during the
authentication process.
The steps in the authentication process are as follows:
2
1. The user logs on by providing logon credentials—typically user name and password—and
Windows XP Professional forwards this information to the security
subsystem of that local computer.
2. Windows XP Professional compares the logon credentials with the user information
in the local security database, which resides in the security subsystem of the
local computer.
3. If the credentials are valid, Windows XP Professional creates an access token for
the user, which is the user’s identification for that local computer. The access
token contains the user’s security settings, which allow the user to gain access to
the appropriate resources on that computer and to perform specific system tasks.
Note In addition to the logon process, any time a user makes a connection to a computer,
that computer authenticates the user and returns an access token. This authentication process
is invisible to the user.