Utility Spotlight

Microsoft Security Essentials

Lance Whitney

The successor to Windows Live One Care, Microsoft Security Essentials is the latest free anti-malware tool from Microsoft. Though you probably already use (or should be using) security software on all your network computers on the job, Microsoft Security Essentials might be a good option for your personal or home-office PCs or virtual environments that aren’t fully protected.

You can download the tool from microsoft.com/Security_essentials, where the site automatically determines the correct version based on your OS.

The installation of Microsoft Security Essentials first triggers Microsoft’s genuine validation tool to make sure you’re running a legal copy of Windows. You’re then prompted to first remove any other anti-malware tools that may conflict with Security Essentials. Finally, the installation gives you the option to scan your computer. At this point, the software will also download the latest definition updates.

Like any standard security tool, Microsoft Security Essentials offers both active and manual scanning. The software provides three types of manual scans: a Full scan, which examines your entire computer; a Quick Scan, which focuses on areas where malware typically likes to hide; and a Customizable Scan, which lets you select the folders and files to check. You can schedule a scan to run daily or weekly and have the scan run only when the PC is on but not in use.

If any malware is found, the software will pop up an alert asking if you want to remove the threat or get more details on it. You can also decide which specific action to take to deal with the potential malware—remove, quarantine or allow the file if you know it’s safe.

A History list keeps a running list of the three different types of items:

  1. All Detected Items – malware-infected files found on your computer
  2. Quarantined Items – files that were disabled and prevented from running but not deleted
  3. Allowed Items – files that you judged safe and allowed to run on your computer

The software automatically includes your PC in the Microsoft SpyNet community, which sends the company information about any threats encountered and how they were treated.

By default, Microsoft Security Essentials automatically checks for the latest virus definition files once a day, though you can manually look for the latest updates.

The software fared well in one of its initial reviews by security testing firm AV-Test.org GmbH. Out of 545,034 viruses, worms, Trojan and other threats, Microsoft Security Essentials caught 536,535 samples for an overall good detection score of 98.44 percent. For adware and spyware, Microsoft Security Essentials stopped 12,935 out of 14,222 samples, earning a detection grade of 90.95 percent. The software also discovered and removed all 25 rootkits that AV-Test.org included in the test.

Unfortunately, you can’t legally use Microsoft Security Essentials in your corporate or business environment—the product’s License Agreement limits its use to home computers. But if you juggle a lot of PCs and virtual environments at home and need to protect them, the product could prove an effective (and free) solution.

Microsoft Security Essentials is compatible with Windows XP, Windows Vista and Windows 7—both 32-bit and 64-bit editions—and even supports Windows XP mode in Windows 7.


Lance Whitney is a writer, IT consultant and software trainer. He’s spent countless hours tweaking Windows workstations and servers. Originally a journalist, he took a blind leap into the IT world in the early ’90s.