Windows Vista™ is the first operating system fully developed under the guidelines of the Security Development Lifecycle (SDL), a security-focused engineering process meant to move security into the very essence of software design; all widely deployed Microsoft products must follow these guidelines.
(For more information about the SDL, check out the book Windows Vista also includes new or upgraded built-in security technologies that actively work to detect and prevent security threats.
With Windows Security Center, you can see which application is acting as your computer's firewall or anti-spyware and antivirus solution.
If your computer is not part of a domain, it is handled by Local Security Policy.
Policy settings are found under Computer Configuration\System Settings\Local Policies\Security Options in the Local Security Policy editor or Group Policy editor.
You can also check the status of firewall, automatic update, and user account control settings.
Windows Security Center is unique in that it monitors the status of third-party applications in addition to built-in Windows technologies.