search icon

An easy-to-use Windows anti-virus and security software with quick, full and customizable scan options

An easy-to-use Windows anti-virus and security software with quick, full and customizable scan options

Vote: (937 votes)

Program license: Free

Program by: Microsoft

Version: 4.10.0209.0

Works under: Windows


Program license

(937 votes)


Program by




Works under:


Microsoft Security Essentials is a freeware antivirus solution designed to protect Windows systems.

Microsoft Security Essentials—often abbreviated MSE—is an antivirus program that monitors for, detects, quarantines and eliminates viruses, spyware, trojan horses, rootkits and so forth. MSE is available free of charge to home users and small business that are using a supported Windows operating system. Microsoft developed and maintained MSE for Windows XP, Windows Vista and Windows 7.

The design goal of MSE was not necessarily to compete with Kaspersky Lab, McAfee, Symantec and so on but rather to ensure that the average user had some form of AV protection active. Prior to MSE, there were many systems running without any protection at all. This intent cause many to prematurely judge MSE. How good could it be was a common line of reasoning. But MSE in practice proved to be quite effective. It may not be as sophisticated as the offerings from some of the bigger names in AV protection, but for the average home user, it is dependable and already installed in many cases.

If you have a home edition of Windows XP, Vista or 7, you can install MSE alongside the OS. If you do not have one of those versions or opted not to install it, the download provided here lets you install it after the fact. When MSE installs, the program configures itself based on your system. That default configuration is fine for the average user, but more advanced users can also customize it. The app provides a robust collection of settings that let you decide when the program updates, when it performs full system scans, the specifics of real-time monitoring, whether it uses System Restore and so forth.

Microsoft has designed MSE to be as hands off as possible. The program even updates itself, which is not an uncommon feature among AV programs, but this one is set by default to check three times throughout the day and update seamlessly in the background. If a hotfix is needed, Microsoft can even push notifications to MSE in order to update the virus definitions and the like. You can disable this if you prefer, but it provides peace of mind to get protection against serious threats as soon as possible.

MSE provides real-time protection. What this means is that the MSE malware detection engine is always running in the background—unless you disable it—checking files, data in memory and more for suspicious aspects. If a suspicious element is found, the engine uses more resources as it ramps up and checks the file, data or whatever more comprehensively. If it finds something, how it behaves depends on the severity. If the malware is severe, MSE will notify you right away and inform you how to proceed. Otherwise, the program will quarantine the malware and notify you take a look at it later.

This program also provides file-based protection, which you can activate manually. Consider a scenario in which you download a ZIP archive from the Internet. You can right-click on that archive and command MSE to run a detection pass on it. Without activating any of the elements, MSE will index through the archive and test all of the files and other resources it comprises looking for malware.

MSE offers both automatic resolution and manual resolution when it detects malware. The most usual automatic resolution is quarantining. This is when MSE walls the suspicious element off. Programs cannot access it, and it does not have access to your system. It is rare that MSE is able to eliminate a threat completely through automatic resolution, which is one of our main gripes with the program.

Manual resolution is when you choose how the program proceeds. In most cases, MSE will notify you and ask you to give it the OK to eliminate the infected items. There are times where this is useful since MSE is particularly aggressive at detecting low-risk threats like key generators. There are instances where MSE will appropriately quarantine an object but then fail to eliminate it when giving the OK. When this does happen, the program is not user-friendly at all. At least the items remain in quarantine, but you will likely have to seek out another program to get rid of the files.

MSE also integrates with System Restore. For those unfamiliar, System Restore is a Windows mechanism that can roll your system back to a certain point. MSE cannot, however, roll your system back to a point before the malware arrived. But it does give you peace of mind when choosing how to proceed. Consider MSE asking you for permission to delete a file, but you are unsure. MSE will create a system restore point so that if anything goes wrong, you can revert the decision.

Microsoft Security Essentials is an effective antivirus tool that outperformed many expectations. Since Windows 7, Microsoft has done a great job changing the common perception of the Windows brand, and the success of MSE arguably played a role in that. If you unsure whether you need more protection than MSE provides, then this is a great start. Pay for more when you know you need it and why.

But—and this is a big but—MSE has been discontinued. How this works is that MSE becomes deprecated when a relevant operating system does. When Windows XP was deprecated in April 2014, MSE for XP was no longer supported. When Windows 7 became deprecated in January 2020 that marked the last operating system that still used MSE. Windows 8 and beyond use Windows Defender, which is an evolution of MSE. This means that new virus definitions and the like are not available for MSE.


  • Freeware for home users
  • Automatically updates
  • Real-time antivirus protection


  • Discontinued
  • Not user-friendly at times

Microsoft Security Essentials is an antivirus and malware scanning product that integrates with Windows Update. As a result, it's historically been easy for users to install and maintain. The built-in Control Panel takes care of most configuration options and Microsoft has extensively tested the software to ensure that it's compatible with any machines running their operating system.

That means it tends to perform quite well. Users will sometimes install an always-on security program only to find that it starts to slow down the system considerably after a couple of reboots. Microsoft Security Essentials doesn't normally have this problem. In fact, it takes advantage of several built-in Windows assets, like the windowing toolkit, to make all of its interface elements move more fluidly than is normally seen.

As a result, it might be a great option for those who can't run a more complex piece of software due to hardware limitations. Redmond's premier security product works on any machine that's capable of running the underlying operating system.

That being said, MSE provides real-time protection and constantly monitors every new file that's stored on your computer. It will check all executable objects against a database of signatures and flag anything that looks suspicious.

As well as traditional virus programs, MSE can detect certain types of worms as well. Depending on the specific settings you pick when you first install the software, it can make System Restore points before removing any specific piece of malware. This can drastically reduce the risk of problems caused by false positives.

Whenever the software makes any kind of change to the system configuration, users are given the option to roll it back with nothing more than a reboot.


  • Lightweight
  • Fast
  • Integrates with Windows Update


  • No longer receiving updates
  • Often imitated

Microsoft Security Essentials is a piece of security software from Microsoft that is meant to cover their systems with minimal protection out of the box. Windows has classically included a number of apps that could easily be called superfluous to the safety and well-being of the system. These apps, like the integrated media player and Internet Explorer, are certainly useful, but it seems strange that it took Microsoft so long to release their version of a basic security package.

Before the final version of this app was released, it was in beta stage for several months. Unfortunately, the final release doesn't seem to have any significant changes or improvements over the beta, but that could be seen as a good thing.

The interface for this piece of software uses a tabbed window with four primary tabs. These tabs allow the user to monitor the current security status of the system, update definitions for harmful code, browse detected threats, and alter the settings.

There are three main scan varieties in Microsoft Security Essentials. These are custom, full, and quick, and they can scan the system even when it's not being used. Scans can be set to occur at certain intervals. You can manually update the database of threat definitions, but the software automatically does that for you on a regular basis. The software includes a tool for restoring the system to a previous point in the event of some sort of system failure.

While this app might be the first of its kind from Microsoft, it's perfectly suitable for home use even by novice users. The app is ideally optimized for beginners, and it's simple enough that those with any digital security experience will be able to easily handle its functions. In fact, the system is so basic that it isn't suitable for large networks or anything beyond a simple home computer. The software hits every checkmark that a basic user would need. One setback is that the app only deletes suspected infected files. It can't disinfect them to salvage the data.

Home computer security is no laughing matter, but many people tend to forgo it altogether. They might do this because it seems too complicated, or they assume nothing could ever happen to them. The sad truth is that anyone could be vulnerable for very innocuous reasons, and leaving yourself unprotected is simply irresponsible. Microsoft Security Essentials might not have the advanced functions and options that premium network-grade security packages have, but it offers an excellent stepping stone to dealing with the more complex systems that provide comprehensive coverage.

This app is highly recommended for those who have no security software installed on their Windows system. It doesn't take much toll on your system, the installation is fast, and it updates in the background.


  • Simple Installation
  • Multiple Scanning Options
  • Resource-Light
  • Updates Automatically


  • Can't Clean Files
  • No Integrated Firewall
  • Very Basic