Is Windows Defender Good Enough in 2018?

When it comes to antivirus software, Windows Defender is the natural choice. In fact, it’s not so much a choice as just the standard state of things, as it comes pre-packed with Windows 10. (In previous Windows iterations it was known as Microsoft Security Essentials.) It’s therefore tempting to just leave it as is and say to yourself that things will probably be fine, right?

But is Windows’ built-in tool enough, or do we still need to rely on the big guns of anti-virus software to keep us safe online? Read on for the lowdown.

This analysis is based on Windows Defender 4.8 and tests carried out in April 2018. Results will inevitably vary over time, but we’ll be doing our best to keep on top of them.

Talking about Windows Defender in isolation won’t get us anywhere. What we need to know is how it stacks up to the biggest antivirus programs that you’ve probably downloaded or even paid for over the years – the McAfees, AVGs and Bitdefenders of the world.

Thankfully, there are several sites dedicated to comparing antivirus software on a monthly basis.

AV Test

AV Test helps users make educated decisions about what antivirus they should use. They rank each antivirus on three factors using a scale from 0 to 6, where 6 is the best. The three elements they test for are Protection, Performance, and Usability. So how did Windows Defender fare?

Pretty well, it seems.


As of April 2018, Windows Defender has scored 5.5 across the three categories. That technically gives it the same “Protection” and “Performance” ratings as antivirus giants like Avast and AVG. It’s worth noting that, at the time of writing, the only anti-virus software to get full marks across the board are AhnLab Internet Security and Avira.

In real terms, according to AV Test, Windows Defender currently offers 100% protection against zero-day malware attacks, slows down web browsing by just 4% (against an industry average of 10%), and out of 1.6 million samples, detected just four legitimate bits of software as malware (industry average is 10).

So Windows Defender is certainly capable of mixing it up with the big boys, which may come as a surprise to those who knew of it several years ago as a somewhat rudimentary solution.

AV Comparatives

It’s hardly representative to look at just one website, though, as AV Tests’ means of testing and criteria will differ slightly from another. On that note, another popular website for antivirus testing is AV Comparatives. Can Windows Defender carry its impressive form over to this site?


Looking at the real-world protection tests, the results are again pretty good. AV Comparatives carried out its tests using a mix of malicious URLs, drive-by downloads, and URLs redirecting users to malware. Windows Defender had a 0% compromise rate, which was better than the 0.4% rates with Avast and AVG, and up there with the flawless scores of Avira, Bitdefender and McAfee.

Windows Defender even picked up the bronze award for false positives, coming in third place in terms of clocking up the least false detection of malware, which we probably all know from experience can cause a whole load of stress.

What Windows Defender didn’t do so well in (the worst out of all the tested antiviruses, in fact), was “user-dependent” malware. In 3.6% of malware instances, Windows Defender gives users the option to execute the malware rather than outright blocking it.

While this is of course better than just failing to detect it – as several of the tested anti-viruses did – it still means you need to be cautious and heed Defender’s warnings when it prompts you.

Small hiccups aside, historical data on both AV Test and AV Comparatives shows a marked improvement in Windows Defender’s performance over the years.


Back in October 2015, Windows Defender received the joint-lowest rating for Protection (3.5/6), amounting to just 95% protection against 0-day malware attacks (this was an alarming 80.5% in September 2015). The industry average at the time was 97.2%, so Windows Defender was decidedly trailing the pack.


At AV-Comparatives, meanwhile, Windows Defender had a 3% compromise rate from July through November 2016. That has been almost directly replaced by the possibility of “user-dependent” security compromises in 2018, which still isn’t perfect but a huge improvement.

Just a few years ago you’d have been laughed off for suggesting that it was enough for you to sit back, install no third-party AV software, and let Windows take care of defending your PC. While we wouldn’t encourage complacency, Windows Defender is now well-proven as a viable antivirus option unto itself.


However, if you want to err on the side of caution, there would be no harm in adding an extra layer of protection over Windows Defender, just to eliminate the minute possibility that something could sneak through the net.

But do you need to worry if all you have is Windows Defender? No, not any more. However, the malware landscape is always shifting, and we’ll keep an eye out for developments that suggest otherwise.

This article was first published in February 2017 and was updated in June 2018.


  1. I took a quick peek at the first link – – and noted that out of 21 tested AV apps, Defender placed an abysmal 20th in protection. Couple that with the fact that Microsoft has created a surveillance, spyware and data-gathering operating system in Windows 10. I wouldn’t touch ‘Defender’ even if it was developed by a reputable 3rd-party.

    I would not have wasted an article on Microsoft’s version for what passes as security for the masses. I would have discussed some of the other solutions that scored extremely well. Kaspersky Labs, for example, had perfect scores in all 3 categories. 11 AV vendors scored 6 out of 6 for protection. Any one of these companies were far more deserving of an editorial nod.

    Even suggesting the use of ‘Defender’ in any scenario is what’s “making tech harder” for the rest of us.

    • “Microsoft has created a surveillance, spyware and data-gathering operating system in Windows 10”
      That ‘feature’ of Win 10 will be there whether you use Defender or Kaspersky or any other anti-virus/anti-malware package.

    • Thanks for that overview Zack. I strongly agree with your observations. The AV industry had its time and value but virusmakers moved to another field like social engineering. Unfortunately that is what “makes tech harder” these days. It is no use spending money on AV software, have a false sense of security, and random click every link and open every attachment received by email.

      Nowadays firewalls, build in AV offers more than enough protection for a technical attack and as Windows-Defender comes build in this indeed made tech easier for most, if not all users.

      Even worse than no av – software and be vigilant all the time, is to use a free subscription and than forget about it after that.
      Windowd Defender will be active right from the first contact to the internet. That is something that no other AV-software can copy. Updates are automatic.

      BTW I have been using windows since version 1.03 never paid for any av-software and my countless pcs and laptops where always virus-free.

      Yes, good enough is good enough. The problem is the user not the device or software

  2. When it comes to AV software, and for that matter any anti-malware software, “good enough” is just not good enough. If you were buying a home security system, would you want just “good enough” to stop most burglars or would you want the one one that stopped all but the most experienced? Granted no security software or system can be 100% effective but it is the number of 9s to the right of the decimal point that make the difference.

  3. I don’t even USE Windows!…LoL! After being “burned” TWICE by XP and getting B.S.O.D.’s two times in a row….and then LOSING about 30% of my data? I was headed in the direction of mac computers, then stumbled upon Linux and never looked back. I have installed and tested almost all of the distros, some of them are truly designed for rocket scientists, others are so easy you wonder why more people don’t use it. Either way? because of its inherent file structure (which recently changed to btrfs and xfs!) The whole OS is a bit more secure than Windows could ever hope to be. Throw in the rootkit hunters, ClamAV….BleachBit an the like…and you can have a secure, stable, solid system that runs faster, and stays running faster than Windows! Windows Defender? is nothing more than a way to make those who aren’t informed feel that their systems are safe and secure.

    • Lol!!! two BSODs on an Operating System that’s long gone caused you to move to linux? and you lost 30% of data, not Microsoft – if you didn’t have backups, then that’s your fault, not Microsofts, Computers by nature will have problems, doesn’t matter what OS they run, if you’re not backing up , you’re going to get ‘burnt’ every time

      Linux is a ‘bit more’ secure than Windows could ever be? How so?

      Yes Microsoft does care about the cash more than anything, but that doesn’t mean it is a bad option, Though I agree defender is useless, but this article is designed to help those ‘ill-informed’ people….

      • Understand this is the era of CD’s…..(DVD’s were on the horizon but weren’t here yet!) and to have to try and save all the data I had on CD’s?….would have net me over at least 20 of them! And while backing up data IS the responsibility of the individual why does that negate the operating system from giving me more than two BSOD’s within a month’s time? So because I didn’t back up my data….then the company that designed the OS is allowed to push out sub-par technology? Hmm……that seems like flawed logic to me.

        You don’t know how Linux is more secure than Windows? Have you ever heard of “iptables” show me the equivalent in Windows. ‘Nuff said.

        Microsoft is not a bad option: for someone else. For me it is….it always WILL be and that’s the end of it. I’m not here to make fun of others, or belittle their decisions regarding the tech they use, I was just describing the tech I use and why. its all good. And we’re cool…..right? LoL!

    • Is there a requirement that every article about Windows has someone that talks about how much better Linux is? When I read an article about Windows I don’t care that someone else uses Linux and how much better they think it is. Congratulations on Linux having a 2% market share of the PC market. Most people work in a place that requires them to support Windows products and we read articles that help with that. Your comments about how superior Linux is unneeded information and quite frankly just a smug response with the intention of showing us just how smart you are compared to those of use that use Windows. So congratulations to you for being the smartest person in the room, at least in your mind. Meanwhile the rest of live in the real world where we read the articles and comments to find out helpful information. Your comments just require us to scroll down the page more. Just thought you should know.

      • I believe the real question should be, why would you pay attention to something that has no value to you? I’m sure there are other comments on here or on other sites you visit, that you scroll past without commenting….I guess you cannot do that in this instance?
        I never proclaimed to be the smartest person in the room. Why is it people get offended when others offer their opinion / point of view / perspective? I never said anything about “people who use Windows are stupid” or anything ELSE of that nature……matter of fact I never mentioned other people period! I was speaking about MY experience with Windows and what I PERSONALLY thought about Windows Defender, since when is that something that should be negative(or in this case “illegal”)? This is the problem with society today, anyone can jump up and claim they’re “offended” by another’s ideals, beliefs, concerns, traditions, and all of a sudden a person is labeled bad, negative, a troll, a bully, a pervert, etc. etc. Well since I live in America? I have a RIGHT to voice my opinions ANYWHERE I see fit…(granted…as long as they don’t cause financial, or physical harm to anyone else!) so to those who DON’T like my comments?….my advice?….”Scroll Past” and ignore them. Or……use your right to reply, and prepare to enter into debate and discussion. (Without insults please!….we’re not in 4th grade! and I’m sure you know how to express yourselves to your bosses, wives, children…etc) but NO ONE gets the green light to come down on someone else because their opinions or views differ. Understand? Good!

        ‘Nuff said!

        • Eddie G. I suggest you re-read your initial post, which has nothing whatsoever to do with “Is Windows Defender Good Enough in 2018?” I respect your right to have an opinion but you have not made one that is on-topic.

        • “This is the problem with society today, anyone can jump up and claim they’re “offended” by another’s ideals…”

          Your personal experience with Windows presented, happened before Windows Defender existed, thus your first post had already added little or no value to the discussion. You shouldn’t take personally, the responses reminding you of this. You mentioned Windows Defender once at the last line of your post, without having used it personally, labeling it as “Nothing more than a way to make those who aren’t informed feel that their systems are safe and secure.” So, you had complained about others making insults in criticizing your post, but you had already done so yourself. After having made a judgmental statement in which you had labeled users of Windows Defender as amateurs, a viewpoint contrary to the one the article had presented, you had in the process insulted me and my knowledge about the Windows operating system. This, after having personally stated that you hadn’t used it since Windows XP. In that case, as a non user, you had little reason to respond to the article at all, and I suspect that you hadn’t read it before commenting. You don’t see me attacking BMW owners in a BMW forum, saying that their vehicles are too expensive to maintain and break all the time, just because I choose to drive an Infiniti. You’re welcome to see if you can find any viruses or malware on my Windows Defender enabled computer. There isn’t any. Could there be reasons for people to question your post from a technical standpoint?

          This is PC World’s test, results close to what was presented here. Did these people who do this stuff for a living, all get it wrong too? If their findings had been vastly different, that I would criticize.

          “I have a RIGHT to voice my opinions ANYWHERE I see fit…”:

          Not on a privately run site. There’s moderators, to deal with trolls, or people who post offensive or off topic material. The people who get banned, just find somewhere else, and post the same things, thinking that the people who banned them must be the problem. I don’t think that will ever change.

          “Well since I live in America”

          People criticizing your posts also live in America, and also have every right to undertake in that activity.

          People’s choice of OS and anti virus software is a subjective thing. I personally feel more knowledgeable after having read the for and against Windows Defender arguments, and I had personally researched Linux after reading your post.

      • I agree some people enjoy changing the subject and reminding us all about how Windows is a piece of junk. Getting some blue screens doesn’t bother me, it’s usually a bad driver or service that can’t load properly (not the software), and I have Event Log to find it. Windows uses up too much memory, yes. Microsoft forces me to download service packs containing things that I don’t need, chewing up my hard drive space, yes. But I have come to understand it very well, and can tweak it by turning off services. Linux doesn’t even offer Microsoft Office, after all this time! Deal breaker for me, I’m afraid. I am one of the people who has for some time used only Windows Defender, and Windows Firewall. I only visit safe sites, and thus don’t get viruses, ransomware, or malware, and so I have found little reason to add software that chews up memory and runs code that I don’t need (my next firewall/AV, if any, will be a lightweight solution). Also, people have become obsessed with cybersecurity, and every piece of software now has its own solution. I just uninstalled Bitdefender after it told me that my browsing is unsecured. I know this, and it isn’t a problem for me.

  4. I use Windows Defender but I admit to being somewhat uneasy about it. That’s the main reason I came here: to discover if there were better alternatives. Thanks.

      • I’ve got basic A+ and Net+ certs, and I can only recommend the free versions that I’ve actually used myself, and on client machines ( I have maintained a small computer repair biz for 10 years)…that said, AVG free, Avast free, and Sophos work very well. There are others, but my experience has been with these. Again, there is not a single anti virus program that stops everything, but occasions of infection will also vary depending on the ‘type’ of sites visited, so there’s a fair amount of discretion involved as well. Malwarebyte’s free is an excellent tool as far as removal of nasty stuff too, just FYI. Good luck and good hunting.

    • You can ease your worries by adding malwarebytes and another av software and setting them to run only when you do an occasional manual scan with them, say once or twice a week or so. Kind of a “second opinion” on Windows Defender’s performance–and catch any nasties it might miss.

  5. Let’s not forget MS’s foray into AV’s some years ago with MSSE (Security Essentials).
    Look where that ended, initially sound but soon left to languish by MS.
    Would you really expect any better result with Defender – I don’t think so!

  6. MS is daily sending updates for Windows Defender so this is not a static thing but in development. Mostly AV software comes as free version but when you really want better quality you have to pay. Since these 3rd party AV solutions do not care much about Windows people often complain of very high CPU and RAM usage caused by Kaspersky, Norton and others. In sum this is rather a complex issue and last but not least, question of cost.

    • Unless you have a PC capable of handling the demands put on the machine by an AV, you’re pretty much going to suffer. I don’t know why the AV’s that exist for Windows eat up so much RAM, but I guess the alternative is to run NO anti-virus and to risk getting hit hard with some form of electronic plague!

  7. A lot of magical thinking in these comments! Windows Defenders paired with the free version of Malwarebytes (Manual Scan) and periodic use of Spyware Blaster will give you protection that is comparable to anything else out there AND it’s FREE… ANDd it doesn’t try to install adware or ceaselessly nag you to upgrade!

    Not sure why all the hate for Windows Defender – it does a decent job as an AV (If you really want something else then use Avast (no longer requires registration and the adware is manageable). That being said, just running an antivirus is no longer enough- you need to supplement with programs like Malwarebytes and hardening of your browsers (Spyware Blaster + Chrome or Firefox).

    Get off your high horse already!

  8. Is Windows Defender good enough? As with all similar software, that depends on the user. Is the computer used only for checking email, watching YouTube or Netflix, and surfing the most widely travelled sites on the web? If so, then it’s probably sufficient. Even then, I would advise using a different product.

    • “Even then you would advise using a different product”? Seriously? That opinion makes absolutely no sense whatsoever.

  9. It is inconceivable to me that the hackers out in the wild know Microsoft code more thoroughly than the MS programmers. Windows Defender and/or MS Security Essentials should be lockdown software that protects all other MS products. MS has singlehandedly created the after-market security software industry, If it wasn’t for MS and Windows that industry would be just a mere shadow of what it is today.

  10. I was an avid Avast! user for several years. Then Avast! pushed their “secure browser” onto my PC without my permission. It started messing up sites I frequently visited, so I uninstalled it. But it left so much Chrome fragments behind that I still had problems with using Edge. I had to do a “Fresh Start” to reload Windows 10 to get rid of all the junk left behind by Avast!. Meanwhile, both my wife and I have been depending upon Windows Defender on our laptops with no problems. Bye-bye Avast! Your arrogance cost you a customer. Defender has proven to be good enough for us.

    • Well done. I went through something similar with Avira and Bitdefender: they both felt like high overhead programs offering me loads of unnecessary features. It seems like you can’t buy a simple anti-virus and firewall program anymore: I’m not interested in exploring new methods of storing my passwords securely. I don’t need a new browser that they say is more secure. I’m not interested in being told that my browser is insecure because the site I’m visiting isn’t https:, which I have no control over. I don’t need a new digital wallet. All of my current payment methods, already have cyber security built in to them.

  11. I really appreciate that the article gives its creation date and latest update date. There should be a rule that all the stuff on the web does this.

  12. Is Windows Defender equqall y effective for Windows 7 and Windows 10? Is ot abetter option on Windows 7, compared to Avast or AVG free anti-virus solutions?

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