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3.11 Windows Firewall
Windows XP Professional SP2 includes new security technologies that affect network protection,
memory protection, web browsing, and e-mail handling. Windows XP Embedded with SP2 includes
these important security changes.
Windows Firewall, previously known as Internet Connection Firewall or ICF, is a protective boundary
that monitors and restricts information that travels between your computer and a network or the
Internet. This provides a line of defense against someone who might try to access your computer from
outside the Windows Firewall without your permission.
In Windows XP Embedded Service Pack 2 (SP2), Windows Firewall is
turned off
by default.
Adjust Your Firewall Settings
Because a firewall restricts communication between your computer and the Internet, you might need to
adjust settings for some programs that prefer an open connection. These adjustments are called
"exceptions."
Windows Firewall now has three settings:
On
,
On with no exceptions
, and
Off
.
On
Windows Firewall is turned on by default, and normally you should leave it that way. When you choose
this setting, Windows Firewall blocks all unsolicited requests to connect to your computer, except for
requests to programs or services selected on the
Exceptions
tab.
On with no exceptions
When you select the
Don't allow exceptions
check box, Windows Firewall blocks all unsolicited
requests to connect to your computer, including requests to programs or services selected on the
Exceptions
tab. Use this setting when you need maximum protection for your computer, such as when
you connect to a public network in a hotel or airport, or when a dangerous virus or worm is spreading
over the Internet.
Tip
：
There is no need to keep
“
Don't allow exceptions
”
selected all the time, because when it is,
some of your programs might not work correctly, and the following services are blocked from accepting
unsolicited requests
：
File and Printer Sharing
Remote Assistance and Remote Desktop
Discovery of network devices
Preconfigured programs and services on the exceptions list
Additional items that you've added to the exceptions list
Note
：
When you select
“Don't allow exceptions”, you can still send and receive e-mail, use an instant
messaging program, or view most Web pages.
Off
This setting turns Windows Firewall off. When you choose this setting, your computer is much more
vulnerable to harm from unknown intruders or viruses from the Internet. This setting should only be
used by advanced users for computer administration purposes, or if your computer is protected by
another firewall.
To adjust your firewall settings
Click Control Panel
In the Control Panel, click Security Center
