Security Essentials is an anti-virus package that has been released by Microsoft into a crowded security software market. The product is free but how does it stack up against the competition?
Download and Installation
The software can be downloaded from the Microsoft Security Essentials website. Versions are available for Windows XP and Vista/7 in both 32-bit and 64-bit installations.
The Vista installer is under 5Mb whilst the XP installer is a little over 8Mb. The installed software uses just 11Mb of disk space. Microsoft have finally proved that it’s possible to create an anti-virus product which doesn’t take 3 days to download and fills your hard disk!
Installation is quick and painless. Following a quick check to ensure Windows is genuine, the product installs in a minute or two. Security Essentials then proceeds to download the latest virus signatures and run a quick scan of your hard disk. The scan took around 12 minutes on a newly-installed XP system — it may not be the fastest, but full scans are rarely necessary.
Interface and Options
The main interface is clean and uncluttered. It will be immediately familiar to anyone using Windows Defender:

Microsoft have used a standard Windows interface which gets the job done. It may not be as pretty as competing products, but does an anti-virus package really need fancy graphics, theming options and other unnecessary widgets?
There are four main tabs:
- Home: displays a summary of protection settings and allows you to start a full system scan.
- Update: allows you to manually download virus signature updates (updates are downloaded automatically so this should rarely be required).
- History: shows a list of detected items and those which you have quarantined or permitted.
- Settings: configuration options for scheduled scans, real-time protection, excluded files or processes, and actions.
The product also adds a “Scan with Microsoft Security Essentials” option to the right-click menu, although real-time protection will be adequate for most users.
Configuration is simple and the default options will be suitable for the majority of users. Even novices will understand most settings and never need to change them. Security Essentials compares favorably with the convoluted and confusing settings offered in some other products.
Virus Detection
Security Essentials detected all the viruses I threw at it. When a virus is encountered, a large system tray pop-up appears so you can remove the infected file, quarantine it, view further details, or allow it.

You can also opt to send virus information to Microsoft (none of the data will be used to identify or contact you).
I cannot guarantee Security Essentials will identify all known viruses or has a better detection rate than other products. However, the level of protection seems to be good and other testers have also been impressed by the results.
Resource Usage
Security Essentials uses around 80-100MB of RAM and 75% of CPU time during a full scan. During normal activity, the application uses less than 8MB of RAM and rarely registers any CPU activity.
Other anti-virus software manufacturers should take note. Many commercial and free products are resource hogs that can make slower systems unusable. Microsoft’s solution has a barely noticeable effect.
The Verdict
Microsoft Security Essentials is everything an anti-virus package should be. It’s simple to use, works well, and does not impair your system. Microsoft’s competitors will argue that it’s less secure and doesn’t have as many features, but they should be worried. Overall, Security Essentials is excellent and I highly recommend it.
The Pros:
- Good virus, malware and spyware protection.
- Clutter-free interface.
- Easy to use and understand.
- Lightweight and unobtrusive.
- Fast and uses minimal resources.
- It’s free.
The Cons:
- Not as many features as some other packages.
- Virus writers might be more tempted to target Security Essentials because it’s from Microsoft.
Link: Microsoft Security Essentials website
See also: Microsoft Release Free Anti-Virus Package







this still doesnt address the core issues with windows. Microsoft seems destined to continue using the NT code base in its new OS. until they transition to a new framework, the old bugs from 2k and XP days are still going to be in Vista/Win7 no matter how many dialogue boxes get in the way.
Apple is upto Rev 7 of OS X now, and has no virus threats? why is that? because they continue to evolve the code base. The switch to Unix was golden for them and instead of inventing their own kernal that would be full of exploits and holes, they went with a tried and true one. MS need to get on that bandwagon sooner rather than later.
October 4th, 2009 at 11:11 pm
Couldn’t agree more, you can’t polish a turd. No matter how much aero gloss you put on it dosent detract from the fact Windows is fundamentally flawed.
October 4th, 2009 at 11:21 pm
Macs have no virus’s because hackers and coders have better things to do than to attack something with a 10% market share. while there at it maybe they will make virus’ for a linux box so they can get another couple percent of infected systems.. If apple ever did make an anti virus solution they would probably take clam av because its free like unix then over charge for it and run it on obsolete hardware.
October 4th, 2009 at 11:37 pm
Thanks for the review, but it lacks a core point (at least for me).
Does it have real-time, online scanning system filtering your emails while you down/up-load them ?
Does it have an option to scan each file you download from the internet ?
Those are key points, that makes – for example – a valid product like ClamWin go almost unknown to the MS Windows audience and for those who do not rely on Outlook (vanilla or Express) for their mailing …
October 4th, 2009 at 11:43 pm
BUT – when it finds something during a scan does it stop the scan or will it continue scanning??
October 4th, 2009 at 11:56 pm
Looks like Microsoft is doing something right for once. Most Anti-Virus software like you said is bulky and uses loads of resources even when idle. I have downloaded and might have to give it a try.
October 5th, 2009 at 12:02 am
it worked really good on my windows xp sp3
althout i have low ram (384 MB) and an old pentium III CPU (930 MHz) .. it detected 2 threats automaticly just after if installed the updates .. the full scan took long time but it removed alot of high and severe threats..
it takes 30 MB of my ram when idle .. idk why !
but i will upgrade my ram to 1256 MB .
October 5th, 2009 at 2:01 am
This might be a good thing. The only feature I didn’t like was that it requires your Windows to be genuine. I can understand the need for MS to get their money on Windows, but there should be a need to stop viruses regardless of if being paid for or not.
October 5th, 2009 at 2:15 am
@W2ttsy
Whilst Windows is far from perfect, viruses can be written for any OS. Unix-based systems are fairly invulnerable, but viruses can target applications with scripting such as office documents, PDFs, or browsers.
In any case, most users remain on Windows no matter how good the alternatives are.
October 5th, 2009 at 4:35 am
Well, I’ll wait for a review by German computer authority c’t magazine…
October 5th, 2009 at 4:36 am
Works very well. I like it. Nice work Microsoft.
October 5th, 2009 at 5:36 am
I might just recommend this instead of Avast to the average user.
Avast’s website is too confusing to the average person. Sticking with Avast myself though.
Norton and McFee are on my list of apps to uninstall from any PC I work on, whether the owner likes it or not.
October 5th, 2009 at 9:40 am
The lack of features could easily be contributed to its name “Security Essentials” after all its not named “Security Suite.” ;)
October 5th, 2009 at 8:00 pm
Someone I know have installed McAfee (Win 7 version) on a Windows 7 RC and it slowed the computer down to take about 15 minutes to start up (and the whole computer is slow at any processing)! I use Kaspersky on my Win 7 RC, but will try this.
October 5th, 2009 at 11:31 pm
@koolinus
In answer to your questions, SE does have real-time scanning which also picks up files you download instantly (actually, for the small files I tested, it gave a virus warning before I’d even clicked “save” because it had found it in the temp folder).
Emails and attachments should be scanned, but I’m not sure about compatibility with every system.
Incidentally, I currently use ClamWin, but I’m switching to MS SE.
October 6th, 2009 at 12:45 am
Hi Craig, Was there some mention of contrast and comparison with competition in there? :) Just tweaking you man.
Always,
Phil
October 6th, 2009 at 4:22 am
Or you could just use Kaspersky, works about 10x better. Im sick of people complaining about viruses, malware, etc. but they all insist on sticking with freeware that doesnt provide real-time scanning or updates for the latest virus’s within 2 hours. Just go and buy a decent AV and IS pack like NOD32, Kaspersky or others
October 6th, 2009 at 12:17 pm
I am concerned with the fact that if everyone starts using Security Essentials, then virus makers will have a huge target to hit, and be more motivated than ever. This is like their golden ticket to mass destruction. They are already jumping for joy.
Competition in the anti-virus market is good, and I have a feeling a lot of people are just thinking that free = good. If you consider the anti-malware solutions that techs use to clean up people’s computers, you would see that they use more than one. One isn’t enough. Seeing is believing, and I’d love to see that Security Essentials in all anyone needs, so I will wait and see. It just seems too good to be true.
October 6th, 2009 at 4:35 pm
It’s done very well in beta for folks, and now that its officially out, the av testers can get a go at it.
So far it’s performing quite well…
http://news.cnet.com/8301-1009_3-10366232-83.html
…And you can can still run it along side other products, like malwarebytes for layered protection.
October 7th, 2009 at 5:55 am
I would rather buy a security product made by a company that devotes 100% of their time to security rather than a product made by a company that devotes just a small fraction of time to it. And when you can get a top-rated product like Norton Internet Security for about $28 in OEM version, it’s just not worth the risk to use something like this from MS. Also, according to the CNET review it does not include behavioral-based detection – only stuff from a list of known malware will be detected. Therefore it won’t block new, unknown malware like NIS will.
October 7th, 2009 at 12:50 pm
@FrankB
The problem for commercial anti-virus providers is they need to prove this year’s product is better than last year’s. That’s why they start adding unnecessary trash.
Also, time is relative. 0.1% of Microsoft’s time is thousands of man-hours. Possibly far more time and resources than their competitors spend on a product.
October 7th, 2009 at 5:40 pm
I have to say that while I agree a solid performing security suite is essential for Windows, this should not be seen as a failure in the OS, simply a measure of the weight of activity by virus creators against a wide spread OS.
As someone has already stated, Macs only represent a small market share and this alone can account for the lack of active virii designed for it.
My greater concern is the insistence on replacing user awareness and training with a software suite. I have had need to clean down many user pcs where various suites including Norton and McAfee had completely missed the infection or been partly disabled by it.
I feel that what we should be doing is educating people on the fundamentals of safe guarding their own security through common sense approaches to computer use rather than increasing dependance on yet more software.
October 7th, 2009 at 8:00 pm
As an software specialist I can’t believe some of the comments that has been posted in favor of this Microsoft’s cheap ( free ) product that has been produced by a corporation that that is only specialized creating
“SOFTWARE GIMMICKS (visually attractive accessible for the masses , it has be it is what they are )” for the superficial popular consumer that has absolutely “0″ idea about how much the present day Viruses has evolved. To say that Microsoft can beat NORTON or KASPERSKY must be the No 1 joke of the modern digital and IT age.
October 8th, 2009 at 1:28 am
@Lennard Jay
Microsoft have taken on and beaten far bigger and more powerful competitors. People see through gimmicks fairly quickly — have MS really been doing that for over 30 years?
But regardless of those issues, MS SE is good. It does a great job without taking over your PC. It may not be as feature-packed as Norton or Kaspersky, but does the average user need everything those products provide?
Try it … you might be surprised.
October 8th, 2009 at 2:06 am
My experience of resource usage is different from yours. With full scan disabled, enabling real-time protection uses around 35% of my quad-core (Windows-7 64; intel Q8200). The anti-malware executable itself sits at 5-10%, but it also seems to put significant load on the copy of svchost.exe running firewall, security and diagnostic services. Oddly enough, turning off the individual activity and download monitoring options in real-time protection makes no difference; it makes me wonder if the overhead is coming from the architecture/framework, not the scanning. Basically I go from 99% idle to around 65% idle, shortly after enabling real-time protection. To me that seems excessive and I’d prefer a more light-weight solution. Would be interested to hear of others’ experiences of CPU usage with this software, in case it’s down to something weird on my configuration.
October 13th, 2009 at 11:31 pm
update to the above: seems to be a conflict with “launchy”, an open source program launcher. Quitting launchy solves the excessive CPU usage.
October 14th, 2009 at 12:01 am
As Wikipedia may not be the best source of information, Security Essentials may not be the best anti virus program. Bottom line is they are both good enough. I find both very useful and more importantly FREE.
Actually I have been running without any protection on all my PCs since Vista RTM and have never had any problems. I just added SE to my win 7 machines because it was free and doesn’t take too many resources.
October 28th, 2009 at 4:38 am