3 min read

Microsoft’s barely there Security Essentials

Microsoft Security Essentials sips system resources so sparingly there's no noticeable effect on a computer's performance.

And yet the free application protects Windows systems from most malware and attacks.


Security Essentials is lightweight compared with Microsoft's earlier, paid-for, OneCare security.

It only uses 280k of system memory on my test machine. The download is 8.5Mb and the installed program occupies about 12Mb scattered between the Program Files and Program Data folders on my C: drive. Of course there could be other components stored elsewhere – getting the full picture about software installations isn't easy when you run Windows 7.

One week has passed since installing the software. There's been no noticable performance hit running Security Essentials. System benchmarks are the same with and without the program installed. This is in stark contrast to Norton Internet Security 2010 which slowed my machine by about 4 percent to begin with, then progressively worsened to the point where it became unusable after ten hours operation.

Microsoft's program took seconds to download, then another five minutes or so to go back and fetch the necessary anti-malware signatures. I'm running Windows 7 beta and am completely up-to-date which meant things went smoothly for me. The Security Essentials installer will insist you download and install all the Windows updates before the application installs.

Scanning goes on for ever

I immediately ran a full system scan and quickly regretted the decision. Scanning isn't fast. The software warns users scans may take some time, but my first scan was still running some six hours after first installing the software. I started another scan before writing this piece and one hour, 15 minutes later the software has only scanned 76,000 items. The indicator bar is only 5 percent of the way across the screen.

It is possible to scan attached drives with the software, but there aren't enough hours in the day to test this.

To date Security Essentials hasn't found anything untoward on this computer. To check the software's effectiveness, I scanned my machine with Panda Cloud Antivirus and Avast. Neither found anything. Nor did Norton Internet Security 2010 find anything before being removed abut 10 days ago.

Google-like interface

Microsoft clearly learnt a thing or two competing with Google in recent years. The user interface on Security Essentials is minimalist. It uses bright red to show problems and is green while everything is safe. There are hardly any controls – compare this to the user interface on Norton Internet Security 2010 which is like the flight deck of the Star Ship Enterprise. The good news is there are few things to tinker with and break. I didn't notice anything needing changes.

When a threat appears online, the real-time protection mode kicks-in and displays a message in a pop-up window. This appears in the bottom right hand corner of the screen. You can dismiss it with a click or get more information. A lot more information than you'll ever need.

Evil empire

You can't argue with Microsoft's price for Security Essentials. It is free. In fact it looks as if it was part of the operating system from the outset. And it may have been. But Microsoft doesn't include it as standard with Windows 7 because of anti-trust considerations. There are people who are wary of using security software from Microsoft – some argue security problems only exist because of flaws in the company's operating systems. Maybe. But the Macintosh is no longer immune from threat and, anyway, that particular genii left the bottle a long time ago.


Norton's paid-for security products are far more advanced than Microsoft Security Essentials – but the name makes that clear. This software does about 90 percent of the job of protecting your computer from attack. If you run a home system, are disciplined about security, run a hardware firewall and keep all you applications and systems software up to date, Security Essentials should protect you from all but the most serious attacks.

Microsoft Security Essentials is not suitable for business users and not the best choice if your home set-up is, well, let's say anarchic. Paid for products may give you better piece of mind.

Microsoft scrubs up well against the free competitors, but without extensive testing I'd rate Avast ahead of Security Essentials, there's also a solid free program from AVG we run on some of our home machines. We experienced some problems with these at the Bennett household as the free versions are difficult to find among the paid-for alternatives at these two sites.

Another alternative is the excellent Panda Cloud Antivirus – one of the best kept secrets in the security business and neither nags nor hides behind a paid alternative.


  • free
  • downloads and installs in minutes
  • works straight away
  • simple, unobtrusive
  • easy to understand
  • no performance hit


  • slow scanning
  • relatively untried
  • doesn't offer the best protection


A basic security product from a big name at an unrivalled price. Get this if you have no budget and are not confident dealing with other free security applications.