The following describes how to determine if your computer is infected with a virus, worm, or trojan, how to recover from an infection, and how to prevent future infections from a virus.
- A virus is code written with the express intention that the virus code replicates itself. A virus tries to spread itself from computer to computer by attaching itself to a host program. It may damage hardware, software, or data.
- A worm is a subclass of virus. A worm generally spreads without user action and distributes complete copies (possibly modified) of itself across networks. A worm can exhaust memory or network bandwidth, causing a computer to stop responding.
- A virus that appears to be a useful program, but that actually does damage, is a "trojan horse."
Take steps to prevent viruses even if you do not visit unknown or untrusted Web sites or open e-mail attachments. There are three steps you can take to start to improve the security of your Windows-based computer:
For step-by-step instructions that explain how to do this for your operating system, visit the following Microsoft Protect Your PC Web site:
www.microsoft.com/protect
On a Windows XP-based computer, the Protect Your PC Web site can automatically detect and configure Internet Connection Firewall (ICF), configure Automatic Updates settings, and
provide information about antivirus software. For additional information about the automated portion of the Microsoft Protect Your PC Web site, click the following article number
to view the article in the Microsoft Knowledge Base:
828931 Frequently asked questions about the automated portion
of the Microsoft Protect Your PC Web site
