Anti-virus software protects you, your privacy and your money. Viruses are not good for the computers and they steal personal information, take over your PC, pop up unwanted adverts and caneven use your computer to attack other people's computers. You may also hear them called malware, trojans, spyware or adware. Anti-virus software protects you against all of them. Anti-virus software has to download and updated regularly over the internet.
You can download Microsoft Security Essentials (free for personal use) or antivirus software such as McAfee.