How do I install and configure Microsoft Security Essentials?

Mark Kaelin walks you through the steps required to install and configure Microsoft Security Essentials, a free anti-virus and anti-malware app.

It may be unfortunate, but the reality of the situation cannot be denied — we live in a time where computer viruses, malware, spyware, Trojan horses, keyloggers, and other nefarious dangers are everywhere. Connecting a computer to a network, especially a network connected to the Internet, should never happen without at least the bare minimum of protections.

Microsoft Security Essentials is a decent antivirus and antimalware application available for free from Microsoft. It integrates seamlessly with the Windows operating system and takes up very little system resources. Installing Microsoft Security Essentials and running the required initial updates and configuration is relatively straightforward.

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As you can see in Figure A, if your computer has no antivirus software, you will get some dire warnings in the Security Action Center. You navigate to the Security Action Center through the Control Panel.

Figure A

Heed dire warnings in the Security Action Center.
We can fix these problems in one action, by downloading and installing Microsoft Security Essentials. The first thing to do is go to the Web site and start the download, as shown in Figure B. You should also uninstall any previously installed antivirus software to avoid conflicts.

Figure B

Download the client.
When the Microsoft Security Essentials download starts, click the Run button, as shown in Figure C.

Figure C

Click Run.
The download and install is very quick. You won't even have time to go and get a cup of coffee (Figure D).

Figure D

The download happens in no time at all.
Figure E shows Microsoft Security Essentials ready to install and explain what it is designed to do.

Figure E

Microsoft Security Essentials is now ready to install.
Of course, you will have to accept the licensing agreement (Figure F) and validate that your copy of the Windows operating system is genuine (Figure G).

Figure F

Accept the license.

Figure G

Validate Windows.
The ready-to-install screen (Figure H) reminds you to uninstall previously installed antivirus applications. It would have been much timelier to have received this suggestion earlier as I suggested.

Figure H

Finally, you're ready to install.


Once Microsoft Security Essentials is installed (Figure I), it will immediately update itself with the latest antivirus definitions (Figure J). This is an important step, as new variations of viruses and malware are released into the wild on a daily basis. No matter which antivirus software you choose to use, always keep it up to date.

Figure I

Microsoft Security Essentials is now installed.

Figure J

Update definitions.
Once the updates are in place, my test PC goes from a red warning that my computer is at risk to a green declaration that my PC is protected, as you can see in Figure K.

Figure K

My PC is now protected.
As further proof, head back to the Security Action Center (Figure L) and check the status of my PC now.

Figure L

Security is back.


From the main page of the Microsoft Security Essentials client application (Figure M), you can see the status of your computer's antivirus security and perform a manual scan. From the other tabs on this screen you can manually ask for virus definition updates and check the history of antivirus activity performed by the application.

Figure M

Configure your computer's antivirus secutiry on the main page.
On the last tab (Figure N), you can set a scheduled time to perform a Microsoft Security Essentials scan. The default is once a week, but you have flexibility to set the schedule to suit your needs.

Figure N

Set a scanning schedule.

Bottom line

Whether you are an individual computer user or the manager of an entire department of Internet-connected computers, the need for antivirus applications is very real. While Microsoft Security Essentials may be merely basic protection, it is an important first line of defense that can work for almost anyone or any organization. With the benefit of a clean install and tight integration with the Windows operating system, it is worth a look no matter how many computers are involved.

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Mark W. Kaelin has been writing and editing stories about the IT industry, gadgets, finance, accounting, and tech-life for more than 25 years. Most recently, he has been a regular contributor to,, and TechRepublic.

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