Windows Defender (formerly Windows AntiSpyware) is a free program that helps protect your computer against pop-ups, slow performance, and security threats caused by spyware and other unwanted software.

Windows Defender features Real-Time Protection, a monitoring system that recommends actions against spyware when it's detected, and a new streamlined interface that minimizes interruptions and helps you stay productive.

Features of Windows Defender :

· A redesigned and simplified user interface – Incorporating feedback from our customers, the Windows Defender UI has been redesigned to make common tasks easier to accomplish with a warning system that adapts alert levels according to the severity of a threat so that it is less intrusive overall, but still ensures the user does not miss the most urgent alerts.
· Improved detection and removal – Based on a new engine, Windows Defender is able to detect and remove more threats posed by spyware and other potentially unwanted software. Real Time Protection has also been enhanced to better monitor key points in the operating system for changes.
· Protection for all users – Windows Defender can be run by all users on a computer with or without administrative privileges. This ensures that all users on a computer are protected by Windows Defender.
· Support for 64-bit platforms and accessibility - Windows Defender supports accessibility and 64-bit platforms. Please be sure to use WindowsDefenderX64.msi for 64-bit platforms.
· Delta definition updates - Windows Defender now downloads smaller delta definition updates when possible which reduces the time required to download and install definition updates. Customers can expect shorter download times when updating their definition updates.
· Free Limited Support - As a part of our commitment to the security of our customers, Microsoft is offering two free support incidents relating to Windows Defender on Windows XP and Windows Server 2003. Examples of valid support scenarios are installation, configuration, definition update, detection and removal errors. Please refer to the Windows Defender support policy for more information.


Important Notes:
· Microsoft Windows AntiSpyware (Beta): Windows Defender (Beta 2) is the final name for Microsoft�s antispyware solution. Current Windows AntiSpyware (Beta 1) customers will be notified automatically to upgrade.
· Beta Support Policy: This is pre-release (beta) software distributed for feedback and testing purposes. Microsoft only provides best effort support through the newsgroups. If Windows Defender (Beta 2) is causing an issue with your system, we recommend removing it by using Add or Remove Programs and even using System Restore if the problem persists.
· Access to Newsgroups: Although formal support is not offered for this beta, we have provided newsgroups to help get your questions answered.