According to PCs For Dummies- Windows 7 Edition, this is the security features of Windows 7 (by the way, this is not just directly copied from the book):
1. Use Microsoft Internet Explorer (the latest version that comes with Windows 7). It comes with the latest security features such as warning the end user when software attempts to install itself on the computer and protection against phishing sites.
2. Windows Defender: The Windows Defender program scan for and identifies start up programs and spyware. Windows Firewall: The firewall helps to guard your computer against the bad guys.
3. Windows Update: Making sure your PC’s software is up-to-date is important because the hackers out there love to target those who stands still.
4. Backup: To keep your stuff safe, I recommend that you back it up. The backup process makes a copy of files on your PC so that if your PC is struck by misfortune, naturally or motivated by malice, the aftermath are not as devastating.
5. Antivirus: Your PC needs a good antivirus program to fight malicious software that slip in from the Internet or arrive on infected media. However, Windows 7 doesn’t come with a built in antivirus, but Microsoft has produced its own antivirus called Microsoft Security Essentials.