This information applies to Windows Internet Explorer 7 and Windows Internet Explorer 8.
Protecting your computer from viruses and other threats isn't difficult, but you have to be diligent.
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 e‑mail, operating system, or files. New viruses appear daily, so check the antivirus manufacturer's website frequently for updates. Most antivirus programs are sold with annual subscriptions, which can be renewed as needed. To find an antivirus scanner, visit the Windows Vista Security Software Providers
Do not open e‑mail attachments. Many viruses are attached to e‑mail messages and will spread as soon as you open the e‑mail attachment. It's best not to open any attachment unless it is something you are expecting. Microsoft Outlook and Windows Mail help block potentially dangerous attachments.
Keep Windows updated. Periodically, Microsoft releases special security updates that can help protect your computer. These updates can help prevent viruses and other computer attacks by closing possible security holes. Make sure that Windows receives these updates by turning on Windows automatic updating. To learn how, 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.