A firewall helps make your computer invisible to online attackers and blocks some malicious software such as viruses, worms, and trojans. A firewall can also help prevent software on your computer from accessing the Internet to accept updates and modification without your permission.
Firewalls come in both software and hardware form, but hardware firewalls are intended for use in addition to a software firewall.
Windows 8, Windows 7, Windows Vista, and Windows XP* include a firewall, which is turned on by default. It is important to have both a firewall and antivirus software turned on before you connect to the Internet.
Read more about firewalls.
*Support for Windows XP ended on April 8, 2014.
For more information, see Support is ending soon.
Antivirus software helps protect your computer against viruses and related malicious software, such as worms and trojans. Antivirus software must be kept up to date. Updates are generally available through a subscription from your antivirus vendor.
Windows 8 includes antivirus protection called Windows Defender. It’s turned on by default. If your computer is not running Windows 7 or Windows Vista, download Microsoft Security Essentials for free.
If you need antivirus software for your business, try Microsoft System Center 2012 Endpoint Protection.
It is important to have both antivirus software and a firewall turned on before you connect to the Internet.
Read more about viruses.
Yes. A firewall helps stop hackers and viruses before they reach your computer, while antivirus software helps get rid of known viruses if they manage to bypass the firewall or if they've already infected your computer.
One way viruses get past a firewall is when you ignore your firewall's warning messages when you download software from the Internet or email.
Read more about how to help protect your computer against viruses.
Antispyware software helps detect and remove spyware from your computer. "Spyware" (also known as "adware") generally refers to software that is designed to monitor your activities on your computer.
Spyware can produce unwanted pop-up advertising, collect personal information about you, or change the configuration of your computer to the spyware designer's specifications. At its worst, spyware can enable criminals to disable your computer and steal your identity.
Windows 7 and Windows Vista include antispyware software called Windows Defender. To help fight both viruses and spyware, you can download Microsoft Security Essentials at no cost. If you download Microsoft Security Essentials, Windows Defender will be disabled automatically. Make sure to uninstall any other antivirus software (whether you installed it or it came preinstalled) on your computer first.
Windows 8 includes antivirus and antispyware software called Windows Defender. Windows Defender for Windows 8 replaces Microsoft Security Essentials. It runs in the background and notifies you when you need to take specific action. If you install a different antivirus program, Windows Defender will be disabled automatically.
Read more about spyware.
Note Some "spyware" is beneficial, as it either helps desirable software run as it's intended, or enables some good software to be offered on a free-with-advertisements basis (such as many online email programs). Most antispyware software allows you to customize your settings so you can enable or disable programs.
Spam filters (sometimes broadly referred to as "email filters") evaluate incoming email messages to determine if they contain elements that are commonly associated with unwanted or dangerous bulk mailing.
If the filter determines that an email message is suspicious, the message usually goes to a designated folder, often called the Junk Folder, and links and other code in it are disabled. Once the message is in the designated folder, you can evaluate it at your convenience.
Microsoft Office Outlook, Outlook.com (formerly Hotmail), and other Microsoft email services fight spam with SmartScreen Filter.
Read more about how to keep spam out of your inbox.
A phishing filter can be a component of a web browser or Internet toolbar, or part of an email program. Phishing filters evaluate websites for signs that they are connected with phishing scams.
Phishing scams use email and websites that look like those that belong to legitimate sources (such as financial or government institutions) but are actually hoaxes. If you click links in the email or enter your user name, password, or other data into these websites, you might give scammers information they can use to defraud you or steal your identity.
Read more about the signs of phishing scams in How to recognize phishing email messages or links.
Parental controls can help you protect your children from inappropriate content, both on the Internet and in computer video games.
Microsoft offers parental controls in Windows 8, Windows 7 and Windows Vista.
Xbox One and Xbox 360 Family Settings offer parental controls that can help you restrict your children's ability to play inappropriate games and watch inappropriate DVD movies.
For more information, see What are parental controls?
If your computer comes with Windows 8, or Windows 7, or Windows Vista installed, you can be assured that you have a built-in firewall as well as antispyware and parental controls. All email programs from Microsoft include a spam and phishing filter. Internet Explorer, the Microsoft web browser, includes phishing protection. If you use another web browser or email program, check the help file to find out if it includes phishing and spam protection.