A firewall is hardware or software
that examines network traffic and either allows the traffic to pass
through it or blocks it, based on the contents of the traffic—the
address it was sent to, the protocol used for the message, and the
network port used to receive the message, among other things. Firewalls
provide protection against worms and hackers probing your system. You
also need the protection against viruses, malware, and spyware that
programs like Windows Defender provide.
Your system should always be behind a
hardware router. A hardware router provides network isolation by hiding
your computer’s network address on a different subnet. Routers can also
be firewalls. And Microsoft provides a software program called
Microsoft Firewall, which you should always have turned on.
Firewalls should be turned on:
• For all types of networks (public, private, and domains)
• For all network connections (Ethernet, Wi-Fi, and mobile broadband)
• For all inbound traffic types—except traffic that you wish to allow
Among the ports you may want to allow are HTTP, HTTPS, FTP, and POP.
To open the Windows Firewall control panel
• Press 
+W and type firewall. Tap or click the Windows Firewall button that appears in your search.
• Press 
+X, select the Control Panel command from the Computer Management menu, click the System and Security link on the Control Panel home page, and click the Windows Firewalls link.
Windows Firewall
has links that allow you to turn the firewall on or off, change
notifications, and allow an app or feature through the firewall.
The Windows Firewall control panel
To turn Windows Firewall on or off
1. Tap or click the Turn Windows Firewall on or off link in the left pane of the Windows Firewall control panel.
The Customize Settings control panel appears .
The Customize Settings control panel
2. Tap or click the Turn on Windows Firewall option.
or
Tap or click the Turn off Windows Firewall (not recommended) option.
The only time you should turn off Windows Firewall is when you are installing a third-party firewall in its place.
To change firewall notifications
Tap or click the Change notification settings link in the Windows Firewall control panel to view the Customize Settings control panel .
Select the Block All Incoming Connections check box to block all attempts by outside sources to connect to your PC and provide maximum
protection for public networks; you can achieve the same result by
turning off sharing or connections in the Network and Sharing Center.
Select the Notify Me When Windows Firewall Blocks a New App check box to
see an alert when an application tries to connect to your system; the
alert also allows you to unblock the port for that particular app. Note
that you can block domains through Group Policy settings.
To allow an application through Windows Firewall
1. Tap or click the Allow an app or feature through Windows Firewall link in the left pane of the Windows Firewall control panel.
The Allowed Apps control panel appears .
The Allowed Apps control panel
2. Tap or click the
check box for the app you want to allow or deny access to; then click
the Public or Private check box to enable that access.
3. To add more programs to this list, tap or click the Allow Another App button to open the Add an App dialog box . Highlight the app, and then click Add.
The Add an App dialog box
4. Tap or click OK to enforce your changes.
Tip
There are many third-party firewall solutions
that you can install, but you only need to have one firewall active at a
time. Windows Firewall is adequate for most users’ purposes.
Tip
It’s a good idea to examine the
Allowed Apps list and remove programs that you aren’t using or that are
unfamiliar to you. Before you remove an app, a file, or anything else,
check that what you are removing isn’t required by your system to
operate correctly. Search online to research the function before
committing to an action.
