Download the latest Windows Defender Definition Updates.

This package will help you install the latest Windows Defender definition updates.

If you encounter problems while trying to install definition updates for Windows Defender, you can download the latest definition update for computers running a 32-bit (x86-based) or 64-bit version of Windows.

Windows Defender is a free program that helps protect your computer against pop-ups, slow performance, and security threats caused by spyware and other unwanted software. It features Real-Time Protection, a monitoring system that recommends actions against spyware when it's detected and minimizes interruptions and helps you stay productive. Now with 2 free support incidents for Windows XP and Windows Server 2003.