Microsoft's free Windows Defender anti-spyware and -adware software ships as standard with Windows Vista and is available as a free download for Windows XP SP2.

  • Operating system tested on: Windows Vista
  • Adware: 3.5 out of 5
  • Spyware: 0.5 out of 5
  • Behaviour-based tests: 5 out of 5
  • Overall: 2.5 out of 5

If Windows Defender had presented itself strictly as an anti-adware program, we'd be less hard on it, but Defender’s website asserts that the software provides 'Spyware protection for free’, and in that respect Windows Defender 1.1 fails.

Windows Defender did detect all 10 of the active adware threats it was exposed to. It detected less than 50 percent of inactive adware samples – hardly a stellar result. In disinfection tests, the program successfully removed 55 percent of adware files and Registry entries, failing to excise PremiumSearch (which messes with Internet Explorer’s home page and favourites) and Starware (which creates an IE search bar).

When it comes to spyware, however, the story is entirely different. In our tests the program neither detected nor disinfected the 10 active spyware threats we introduced. It detected only 7 percent of the inactive password stealers we threw at it.

Windows Defender did excel in behaviour-based protection. It detected all additions to the 'Run' keys (HKCU and HKLM) and the startup folder, as well as all changes to the Internet Explorer search and start pages and the Hosts file.

Windows Defender is easy to configure. It requires little user interaction beyond the option of choosing a low, medium or high level of security, and it was the only stand-alone antispyware program we've tested that by default has a regularly scheduled scan. In Vista, it is the only antispyware tool that integrates with Internet Explorer 7.0 Protected Mode to permit scanning of downloaded files before they are saved or executed.

You should note, however, that telephone support for the program is expensive. After two free calls, you must pay $35 per request.

Windows Defender: Specs

  • PC with an Intel Pentium 233MHz or higher processor
  • Pentium III recommended
  • Windows XP Service Pack 2 or later, or Windows Server 2003 Service Pack 1 or later
  • 64MB RAM, 128MB RAM recommended
  • 20MB hard disk space
  • Microsoft Internet Explorer 6.0 or later
  • internet access with at least a 28.8Kbps connection
  • Windows Installer version 3.1 or higher (visit the Microsoft Download Center to download the installer)
  • PC with an Intel Pentium 233MHz or higher processor
  • Pentium III recommended
  • Windows XP Service Pack 2 or later, or Windows Server 2003 Service Pack 1 or later
  • 64MB RAM, 128MB RAM recommended
  • 20MB hard disk space
  • Microsoft Internet Explorer 6.0 or later
  • internet access with at least a 28.8Kbps connection
  • Windows Installer version 3.1 or higher (visit the Microsoft Download Center to download the installer)

OUR VERDICT

Windows Defender works well against adware and offers solid behaviour-based protection, but if a piece of malicious spyware slips past Defender’s first line of defence, you’ll need something else to clean up the mess.

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