Firewall: frequently asked questions
Here are answers to some common questions about firewalls.
What is a firewall?
A firewall is software or hardware that checks information coming from the Internet or a network, and then either blocks it or allows it to pass through to your computer, depending on your firewall settings. Why do I need a firewall?
A firewall can help prevent hackers or malicious software (such as worms) from gaining access to your computer through a network or the Internet. A firewall can also help stop your computer from sending malicious software to other computers. Even if you think there is nothing on your computer that would interest anyone, a worm could completely disable your computer, or someone could use your computer to help spread worms or viruses to other computers without your knowledge. What does "allowing a program through the firewall" mean?
Allowing a program through the firewall, sometimes called unblocking, is when you create an exception to enable a particular program to send information back and forth through the firewall. You can also allow a program through the firewall by opening one or more ports. For more information, see Allow a program to communicate through Windows Firewall. What are the recommended settings for Windows Firewall?
We recommend the default firewall settings:
* The firewall is on.
* The firewall is on for all network locations (Home or work, Public place, or Domain). * The firewall is on for all network connections.
* The firewall is blocking inbound connections that do not match an exception. How can I be sure that Windows Firewall is on?
Windows Firewall is on by default in this version of Windows. To make sure it has not been turned off, follow these steps: 1. Click to open Windows Firewall.
2. Click Turn Windows Firewall on or off. If you are prompted for an administrator password or confirmation, type the password or provide confirmation. 3. Click On (recommended), and then click OK.
What are some of the things that a firewall can't prevent? * Email viruses
Email viruses are attached to email messages. A firewall can't determine the contents of email, so it can't protect you from these types of viruses. You should use an antivirus program to scan and delete suspicious attachments from an email before you open it. Even when you have an antivirus program, you should not open an email attachment if you're not positive it's safe. For more information, see Avoiding email viruses. * Phishing scams
Phishing is a technique used to trick computer users into revealing personal or financial information, such as a bank account password. A common online phishing scam starts with an email message that appears to come from a trusted source but actually directs recipients to provide information to a fraudulent website. Firewalls can't determine the contents of email, so they can't protect you from this type of attack. For more information, see Phishing Filter: frequently asked questions. Why can't I change some Windows Firewall settings?
If your computer is connected to a domain, your system administrator might be controlling those settings through Group Policy. Where can I see advanced details about exceptions?
You must be logged on as an administrator to perform these steps. The new Windows Firewall with Advanced Security is a Microsoft Management Console (MMC) snap-in that provides more advanced options for IT professionals. With this firewall you can set up and view detailed inbound and outbound rules and integrate with Internet Protocol security (IPsec). Follow these steps to open Windows...