Windows Defender

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.

Malicious Software Removal Tool

The Microsoft Windows Malicious Software Removal Tool checks computers running Windows XP, Windows 2000, and Windows Server 2003 for infections by specific, prevalent malicious software—including Blaster, Sasser, and Mydoom—and helps remove any infection found. When the detection and removal process is complete, the tool displays a report describing the outcome, including which, if any, malicious software was detected and removed.

Winzip Zip Utility

Compression utility for Windows

Zone Alarm

Free software blocks hackers and prevents viruses & spyware from stealing your personal data and sending it out to the Internet. Also, works great with any antivirus software.