<A target="_blank" href="http://www.computerworld.com/s/article/9216467/Remove_Windows_Defender?source=rss_news&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+computerworld%2Fnews%2Ffeed+%28Latest+from+Computerworld%29">Windows Defender is part of the software bundled with Vista and Win7.</A> It's a real-time anti-virus program, one that looks at each file as you open it. If you've decided to use another anti-virus program you may want to remove Defender.