What's new for security

The Security Center

Windows Firewall

Automatic Updates

Internet Explorer

The pop-up blocker in Internet Explorer

Outlook Express

Data Execution Prevention

Other useful information:

Find the latest security information from Microsoft online

Find security solutions for IT Professionals and network administrators on TechNet

What's new for security

The Security Center

Windows Firewall

Automatic Updates

Internet Explorer

The pop-up blocker in Internet Explorer

Outlook Express

Data Execution Prevention

Other useful information:

Find the latest security information from Microsoft online

Find security solutions for IT Professionals and network administrators on TechNet

Helping to protect your computer with a firewall

Why you need a firewall. A firewall is a protective boundary between a computer (or a network of computers) and the outside world, where people or programs might try to access your computer without invitation. Hackers commonly use software that scans the Internet looking for computers with unprotected Internet connections. This software sends a very small message to your computer. If your computer does not have a firewall, your computer will automatically answer the message and thus announce that it is unprotected. But if you have set up a firewall, it will receive such messages and not answer them, so hackers won't even know that your computer exists.

Firewalls can be either hardware or software. A hardware firewall is a piece of equipment that you physically connect to your network. It monitors all aspects of the communications that are sent and received, and inspects the source and destination address of each message that it handles. This provides security in helping to prevent intrusions to your computer or network. A software firewallperforms a similar function by using a program inside your computer instead of an external device.

Microsoft Windows XP Service Pack 2 (SP2) has a software firewall that's built in and turned on for you. This firewall, called Windows Firewall, is turned on by default so that a level of protection is in place right away. It monitors communications in the same way a hardware firewall does. Windows Firewall restricts information that comes to your computer from other computers, giving you more control over access to your data, and providing a line of defense against people or programs that try to access your computer without invitation. Regardless of whether you choose to take advantage of the Windows Firewall or another firewall available to you, keeping the firewall turned on and updated is one of the important keys to helping to protect your computer's security.

Hardware and software firewalls can be used on the same computer. By default, Windows Firewall is enabled on all connections.

Click Related Topics for information about how to:

• Understand how Windows Firewall works.
• Enable or disable Windows Firewall.

Helping to protect your computer with a firewall

Why you need a firewall. A firewall is a protective boundary between a computer (or a network of computers) and the outside world, where people or programs might try to access your computer without invitation. Hackers commonly use software that scans the Internet looking for computers with unprotected Internet connections. This software sends a very small message to your computer. If your computer does not have a firewall, your computer will automatically answer the message and thus announce that it is unprotected. But if you have set up a firewall, it will receive such messages and not answer them, so hackers won't even know that your computer exists.

Firewalls can be either hardware or software. A hardware firewall is a piece of equipment that you physically connect to your network. It monitors all aspects of the communications that are sent and received, and inspects the source and destination address of each message that it handles. This provides security in helping to prevent intrusions to your computer or network. A software firewallperforms a similar function by using a program inside your computer instead of an external device.

Microsoft Windows XP Service Pack 2 (SP2) has a software firewall that's built in and turned on for you. This firewall, called Windows Firewall, is turned on by default so that a level of protection is in place right away. It monitors communications in the same way a hardware firewall does. Windows Firewall restricts information that comes to your computer from other computers, giving you more control over access to your data, and providing a line of defense against people or programs that try to access your computer without invitation. Regardless of whether you choose to take advantage of the Windows Firewall or another firewall available to you, keeping the firewall turned on and updated is one of the important keys to helping to protect your computer's security.

Hardware and software firewalls can be used on the same computer. By default, Windows Firewall is enabled on all connections.

Click Related Topics for information about how to:

• Understand how Windows Firewall works.
• Enable or disable Windows Firewall.

Why use scheduled updates to help protect your computer?

If you have not turned on Automatic Updates, your computer is more vulnerable to viruses and other security threats. When you turn on Automatic Updates, Windowsroutinely checks the Windows Update Web site for high-priority updates that can help protect your computer against attacks. High-priority updates include security updates, critical updates, and service packs.

Scheduled updates offer:

• Convenience

  You don't have to remember to visit the Windows Update Web site or other online security sites to get updates. And you don't have to choose which updates are most important for protecting your computer—Automatic Updates looks for security updates, critical updates, and service packs, and installs them on the schedule that you set.

• Reliability

  Updates are downloaded behind the scenes whenever you're connected to the Internet. The downloading process doesn't interfere with other downloads or interrupt you while you work. If you disconnect from the Internet before updates are fully downloaded, the download process will continue the next time you connect to the Internet. Don't forget, however, that updates must be installed to take effect. When you schedule updates, Windows automatically installs them for you, unless you choose to be notified and then install them yourself.

• Up-to-date software

  You set the schedule for Windows to install new updates. This means thatWindows is routinely checking for and installing any important updates that your computer needs. Even if you choose to be notified and install updates yourself, you still learn about important updates as they are released. By scheduling updates, you can quickly and easily keep your computer up to date—without thinking about it.

Why use scheduled updates to help protect your computer?

If you have not turned on Automatic Updates, your computer is more vulnerable to viruses and other security threats. When you turn on Automatic Updates, Windowsroutinely checks the Windows Update Web site for high-priority updates that can help protect your computer against attacks. High-priority updates include security updates, critical updates, and service packs.

Scheduled updates offer:

• Convenience

  You don't have to remember to visit the Windows Update Web site or other online security sites to get updates. And you don't have to choose which updates are most important for protecting your computer—Automatic Updates looks for security updates, critical updates, and service packs, and installs them on the schedule that you set.

• Reliability

  Updates are downloaded behind the scenes whenever you're connected to the Internet. The downloading process doesn't interfere with other downloads or interrupt you while you work. If you disconnect from the Internet before updates are fully downloaded, the download process will continue the next time you connect to the Internet. Don't forget, however, that updates must be installed to take effect. When you schedule updates, Windows automatically installs them for you, unless you choose to be notified and then install them yourself.

• Up-to-date software

  You set the schedule for Windows to install new updates. This means thatWindows is routinely checking for and installing any important updates that your computer needs. Even if you choose to be notified and install updates yourself, you still learn about important updates as they are released. By scheduling updates, you can quickly and easily keep your computer up to date—without thinking about it.