Windows Defender review, free download

by Julie Splinters - - | Type: Anti-spyware

Windows Defender is a free anti-spyware program made by the leading software company to add native spyware protection to its most popular product – the Microsoft Windows operating system.

The final release of Windows Defender is the result of almost two years long testing and development started with the release of Microsoft AntiSpyware Beta 1 based on GIANT AntiSpyware, a popular spyware remover back in 2004. In the beginning of 2006, Windows Defender Beta 2 has been released. This version is very similar to the final product. However, the latter is definitely better and more solid.

We have tested the program on several different setups including badly infected machines and absolutely clean computers that were never infected with any viral parasites, spyware and malware threats. Tests revealed that Windows Defender is an effective, reliable and easy-to-use product that does not produce false positives and provides sufficient protection against most types of spyware, adware, browser hijackers and other malicious pests. However, it often fails detecting and eliminating widely spread viral threats like trojans, backdoors or worms. Moreover, Windows Defender is ineffective against emerging, new infections, although it uses heuristics.

Windows Defender’s installation is quick and easy, but only if you have a genuine copy of Windows, which doesn't have problems with the validation process and everything always goes smoothly. Otherwise, installing Windows Defender might be difficult and sometimes even impossible.

The program is launched as any other regular program. But usually you don't have to run it manually, as Windows Defender automatically loads on every Windows startup. Integrated real-time protection starts also.

Once the application is running you can start scanning your system. Windows Defender allows choosing between three scan modes: Quick Scan, Full Scan and Custom Scan. The first one enables an intelligent scan for parasites in common locations. Full Scan thoroughly examines the entire file system including not only system and application files, but also archives and suspicious objects not present in spyware definitions database. Custom Scan allows the user to select, which local hard drives to check. Each of three scans needs different time to complete. In our tests Quick Scan did not take more than three minutes, while Full Scan required almost an hour. During each of the scans Windows Defender checks all running processes, analyzes the Windows Registry and examines files and folders. The program scans all essential system components leaving no chances for most spyware parasites to hide.

Scan reports are informative. The spyware remover displays exact parasite location, associated files, related registry entries and threat description.

The program uses large spyware definitions database updated on a regular basis. The user can either update it manually, or turn on automatic updates. In our tests both functions worked as intended. However, a lot of users had or still experience problems updating the application.

Apart from common tools – Quarantined items and Allowed items – Windows Defender offers one additional utility – Software Explorer. This integrated tool provides details on startup programs, currently running applications, system networking components and software connected to the Internet.

One of the strongest sides of Windows Defender is its powerful and customizable real-time protection. However, it's definitely not the best one available on the market today. Popular anti-spyware programs like STOPzilla, Spy Sweeper or SUPERAntiSpyware outperform Windows Defender in this field.

Windows Defender has simple and user-friendly interface. The program has got almost the same look as its Beta 2 version had. However, the updated look is more convenient and thought-out.

The program's official web site is www.microsoft.com.


Windows Defender is a decent anti-spyware program. It is free, powerful enough and yet very easy-to-use. However, it identifies and completely removes only regular spyware and adware parasites as well as some well-known, relatively old malware and viral threats. Unfortunately, Windows Defender does not provide reliable protection against widely spread trojans, worms and other malicious software. In other words, the program cleans most infections, but often cannot eliminate the cause, so the system gets re-infected. But if you have good antivirus program installed, then Windows Defender is just what you need.

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About the author
Julie Splinters
Julie Splinters - Malware removal specialist

Julie Splinters is the News Editor of 2-spyware. Her bachelor was English Philology.

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  1. Casandra says:
    February 8th, 2012 at 6:04 am

    The review is good but I tested it and not satisfied.

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