•New option to display Windows Defender system tray icon even when there are no pending actions needed.
• Enhanced performance through a new scanning engine.
• Streamlined, simplified user interface and alerts.
• Improved control over programs on your computer with enhanced Software Explorer.
• Multiple language support with globalization and localization features.
• Protection features for all users, whether or not they have administrator rights on the computer.
• Support for assistive technology for individuals who have physical or cognitive difficulties, impairments, and disabilities.
• Support for Microsoft Windows XP Professional x64 Edition.
• Automatic cleaning according to your settings during regularly scheduled scans.

...Windows 2000 users might want to start looking for alternative protection.

At the RSA Europe conference in Nice, France, Microsoft announced the general availability of Windows Defender for Windows XP users and made it clear that the software will no longer support Windows 2000, which will be out of mainstream life cycle support in October 2006.