Microsoft Windows Defender

This definition is part of our Essential Guide: Windows 10 security guide to fortify your defenses
Contributor(s): Eddie Lockhart

Windows Defender is an antimalware product included in Windows 8 that can protect against viruses, Trojan horses, worms and other attacks. It defends PCs by providing real-time protection and anytime scanning options.

Released in 2006, Windows Defender was originally an antispyware product only. It was available as a security add-on for Windows XP users and was included in the release of Windows Vista.

The Windows Vista version of Defender marked the first time it could run in a security-enhanced (SE) environment.

This version, along with the Windows 7 version, only scans files that have been modified since the most recent scan; it scans files as they are downloaded.

The Vista version also introduced Software Explorer, which provides information that the Task Manager does not, including a complete display of installed software.

Definitions (files that keep track of potential software threats), must be updated for Windows Defender to be effective. Defender uses definitions to alert users of potential risks. In addition, it works with Windows Update to automatically install new definitions as they are released.

Windows 8 saw Defender evolve in two major ways. First, it could protect against more than just spyware. Second, it is enabled by default in Windows 8.

Unfortunately, Windows Defender is still not a full-featured security offering, missing key aspects that other antimalware platforms are not. For example, it cannot configure the frequency of definition updates, does not offer granular control of task-scheduling and lacks centralized management capabilities. Most importantly, its level of protection is simply not good enough for the enterprise.

As such, it is primarily a consumer-oriented security tool, geared toward those who do not want to purchase protection and want to steer clear of other free options.

It does have the advantage of knowing the Windows OS better than any other tool because it is a Microsoft product. This means it excels at removing malware if it is detected. But, it is also a target as some malware is designed specifically to attack and disable Defender.

This was last updated in March 2015

Continue Reading About Microsoft Windows Defender



Find more PRO+ content and other member only offers, here.

Join the conversation


Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

What antimalware software do you use and why?
Most important to me is that you don't rely on one tool. Windows Defender is a good start, but after I scan with it, I turn it off and then use MalWareBytes, mainly because it's free, but also because it's proven effective in combination with MWD.
I use mult-layered defense against malware, because a long time ago, I discovered that nothing finds everything.  I rely on the multiple layers to catch as much as possible   I discovered even though that with current definition tables Windows Defender does a poor job of protecting you.  I give everything the benefit of the doubt, though, and that is why I went back to my layered defense.
I use 2 running all the time, Spybot Search and destroy and AVG. They both are free and I use Malwarebytes almost weekly as a catch all.


File Extensions and File Formats