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.
If you're running Windows XP
Service Pack 2 (SP2), Windows Firewall is turned on by default.
However, some computer manufacturers and network administrators might
turn it off.
To open Windows Firewall
1. | Click Start and then click Control Panel. |
2. | In the control panel, click Windows Security Center. |
3.
| Click Windows Firewall. |
Note
You do not have to use Windows Firewall—you can install and run any
firewall that you choose. Evaluate the features of other firewalls and
then decide which firewall best meets your needs. If you choose to
install and run another firewall, turn off Windows Firewall.
How Windows Firewall Works
When
someone on the Internet or on a network tries to connect to your
computer, we call that attempt an "unsolicited request." When your
computer gets an unsolicited request, Windows Firewall blocks the
connection. If you run a program such as an instant messaging program
or a multiplayer network game that needs to receive information from
the Internet or a network, the firewall asks if you want to block or
unblock (allow) the connection. You should see a window like the one
below.
If
you choose to unblock the connection, Windows Firewall creates an
exception so that the firewall won't bother you when that program needs
to receive information in the future. To learn more about exceptions,
see the Using the Exceptions Tab section of this article.
Tip:
Although you can turn off Windows Firewall for specific Internet and
network connections, doing this increases the risk to your computer's
security.
What Windows Firewall Does and Does Not Do
Help block computer viruses and worms from reaching your computer. | Detect or disable computer viruses and worms
if they are already on your computer. For that reason, you should also
install antivirus software and keep it updated to help prevent viruses,
worms, and other security threats from damaging your computer or using
your computer to spread viruses to others. For more information, see Frequently Asked Questions About Antivirus Software. |
Ask for your permission to block or unblock certain connection requests. | Stop you from opening e-mail with dangerous attachments.
Don't open e-mail attachments from senders that you don't know. Even if
you know and trust the source of the e-mail you should still be
cautious. If someone you know sends you an e-mail attachment, look at
the subject line carefully before opening it. If the subject line is
gibberish or does not make any sense to you, check with the sender
before opening it. |
Create a record (a security log),
if you want one, that records successful and unsuccessful attempts to
connect to your computer. This can be useful as a troubleshooting tool.
Source
| Block spam or unsolicited e-mail
from appearing in your inbox. However, some e-mail programs can help
you do this. Check the documentation for your e-mail program or see Fighting Unwanted Spam to learn more. |