Install an antivirus program. Installing an antivirus program and keeping it up to date can help defend your computer against viruses. Antivirus programs scan for viruses trying to get into your email, operating system, or files. New viruses appear daily, so set your antivirus software to install updates automatically.
Don't open email attachments unless you're expecting them. Many viruses are attached to email messages and will spread as soon as you open the email attachment. It's best not to open any attachment unless it's something you're expecting. For more information, see When to trust an email message.
Keep your computer updated. Microsoft releases security updates that can help protect your computer. Make sure that Windows receives these updates by turning on Windows automatic updating. For more information, see Turn automatic updating on or off.
Use a firewall. Windows Firewall (or any other firewall) can help alert you to suspicious activity if a virus or worm attempts to connect to your computer. It can also block viruses, worms, and hackers from attempting to download potentially harmful programs to your computer.
Use your browser's privacy settings. Being aware of how websites might use your private information is important to help prevent fraud and identity theft. If you're using Internet Explorer, you can adjust your Privacy settings or restore the default settings whenever you want. For details, see Change Internet Explorer 9 privacy settings.
Use a pop-up blocker with your browser. Pop-up windows are small browser windows that appear on top of the website you're viewing. Although most are created by advertisers, they can also contain malicious or unsafe code. A pop-up blocker can prevent some or all of these windows from appearing.
The Pop-up Blocker feature in Internet Explorer is turned on by default. To learn more about changing its settings or turning it on and off, see Change Internet Explorer 9 privacy settings.
Turn on User Account Control (UAC). When changes are going to be made to your computer that require administrator-level permission, UAC notifies you and gives you the opportunity to approve the change. UAC can help keep viruses from making unwanted changes. To learn more about turning on UAC and adjusting the settings, see Turn User Account Control on or off.