All Windows systems need antivirus software, even if it's free antivirus software. The Windows Defender software built into Windows 10 has gotten much better, but it still can't quite match the best third-party paid offerings. We believe it's worth paying for Windows antivirus software because you'll get the best protection coupled with the latest updates and the most useful features.
Our top pick overall is Kaspersky's Windows antivirus lineup, which combines excellent malware protection with a moderate system impact, a full slate of extra features (such as a hardened web browser, webcam protection and file encryption) and an easy-to-use interface.
Right behind it are Bitdefender, whose cheapest paid product is the best bargain in antivirus software, and Norton, which offers excellent protection with optional identity protection. Trend Micro and McAfee also have very good malware protection, but had a heavier impact on system performance; ESET's protection is a half-step below the rest.
Latest Security Alerts and Threats
— Two flaws that permitted full-system takeover were found in Trend Micro Premium Security and Maximum Security and their accompanying password manager, which is also distributed as Trend Micro Password Manager. ADVICE: Trend Micro has patched all three programs, so update them if you use them.
— All versions of Kaspersky antivirus software for Windows released since the fall of 2015 inadvertently let websites track users, a German journalist discovered. ADVICE: Kaspersky has patched the flaws, so make sure your Kaspersky software is up to date.
— A flaw in Bitdefender Antivirus Free Edition permitted full-system takeover. ADVICE: BItdefender has patched the flaw, so make sure your software is up to version 220.127.116.11.
The best Windows antivirus software overall
Kaspersky's Windows products have excellent malware-detection scores and a light-to-moderate system-performance impact, the two most important criteria in our rankings. The basic program, Kaspersky Anti-Virus, has dedicated ransomware protection, a virtual keyboard and a convenient online account portal. But at this price level, it's beaten by Bitdefender Antivirus Plus, which has even more features.
Kaspersky Internet Security is our top choice among the midrange packages. It has parental controls, a secure browser, anti-theft protection for laptops, webcam protection and a VPN client that kicks in when you connect to an open Wi-Fi network. It also includes software for macOS, Android and iOS.
The premium antivirus suite, Kaspersky Total Security, adds backup software, file encryption, a file shredder and a password manager. It's our favorite among all the premium security suites.
Strong protection on the cheap
Bitdefender Antivirus Plus is our top choice among basic antivirus products. It has nearly perfect malware-detection scores and a very light system performance impact, and it also offers the most value, with a password manager, a secure browser, VPN client software, a file shredder and protection against encrypting ransomware. It also automatically stops scans if it senses you're playing a computer game.
The midrange Bitdefender Internet Security adds parental controls, file encryption, webcam protection and a two-way firewall, while Bitdefender Total Security tops off the lineup with an anti-theft feature for laptops and a system optimizer. The best deal is the Bitdefender Family Pack, which puts Total Security on up to 15 devices for (a frequently discounted) $120 per year.
A security and privacy Swiss Army knife
All of Norton's antivirus products offer excellent malware protection, and the once-crushing system-performance load is now much lighter. But Norton's packages come with fewer security features than competing products, even after a recent overhaul that resurrected the old Norton 360 nameplate and added identity-protection options and unlimited VPN service.
The bare-bones Norton AntiVirus Plus has a password manager, but no webcam protection. You'll get that, plus a VPN client and more online storage, with the otherwise identical Norton 360 Standard. Norton 360 Deluxe adds parental controls and licenses for up to five devices, plus more online storage.
For an extra $50 per year, you can gets Norton 360 with LifeLock Select, which adds LifeLock identity protection plus even more storage space. Topping out the list are Norton 360 with LifeLock Advantage and Norton 360 with LifeLock Ultimate, which expand the identity-protection services but offer the same malware-protection features as Norton 360 Deluxe. If you're looking for just an antivirus solution, however, even a midrange Bitdefender or Kaspersky package will give you more useful security tools.
Flawless protection, but a heavy load
Trend Micro offers very good malware protection, but its detection engine creates a heavy system-performance impact. Its entry product, Trend Micro Antivirus+ Security, is pretty basic in terms of extra tools. Parental controls and a system optimizer and file shredder come with the midrange Trend Micro Internet Security. The top-end Trend Micro Maximum Security adds a password manager, a secure browser and file encryption, but none of Trend Micro's programs include a two-way firewall.
Lots of devices covered for low fee
McAfee's malware detection has improved greatly in the past couple of years, but it still slows down PCs a lot during scans. Despite that, McAfee AntiVirus Plus is a bargain; $60 per year buys software for up to 10 (in fact, it's unlimited) devices, whether they run Windows, OS X, iOS or Android, and the software comes with a file shredder and a two-way firewall. (A single-device license costs $40.)
McAfee Internet Security adds one of the best password managers in the business, but to get parental controls, you'll have to spring for the 10-device license of McAfee Total Protection or its sibling McAfee LiveSafe, which comes pre-installed on many new PCs. The multi-device licenses of those two security suites also come with an identity-protection service, but none of the McAfee products have a secure browser or webcam protection.
ESET is one of the biggest antivirus names in Europe, but while it has a moderate system-performance load, its malware-detection rate isn't as spectacular as those of the other antivirus brands on this page. The entry-level ESET NOD32 Antivirus is easy to use but has few useful extra tools. ESET Internet Security adds a network scanner, webcam protection, parental controls and a hardened web browser.
The top-billed ESET Smart Security Premium tosses in file encryption, a virtual keyboard and a password manager. To get software for multiple platforms, you'll need the ESET Multi-Device Security Pack, which oddly offers the midrange Windows product instead of the premium one, but does include antivirus software for Linux.
Antivirus Buying Tips
The truth is that any of these six brands will protect your computer from infection very well. But before you buy antivirus software, you have to figure out what you will use it for.
If you have children at home, then you'll want to consider the various brands' midrange antivirus products, most of which include parental controls. Do you want an all-encompassing security solution? Many of the top-priced, premium products include backup software and VPN accounts. Or are you a techie who understands the risks? A low-priced basic program might be all you need.
Then you'll have to determine how many machines you need to protect. Got a single, solitary PC? Most vendors offer single-device licenses. Got a desktop, a laptop, a tablet and a smartphone? Multi-device, multi-platform licenses are available for most midrange and premium packages. Does your whole family need to protect its devices? Some vendors offer plans that cover 10, or an unlimited number of, devices on multiple platforms.
But the days when you could walk into a store and pay a one-time fee for an antivirus product are long gone. All the vendors now sell their software licenses as yearly (or multiyear) subscriptions. You'll always be getting the latest software, and you can download and install the software straight from the internet. But you'll be paying again every year.
Antivirus Pricing and Features
You don't have to spend a lot for antivirus software. Many products are sold online for much less than their list prices. But each brand offers at least three configurations of features and pricing -- basic, midrange and premium -- with every step up adding more features to the one before.
Think of antivirus packages like cars at an auto dealership. You can get a base-model Toyota Camry that has few extra frills but will get you from place to place just fine. For a few grand more, you can buy a Camry with satellite radio, but no heated side-view mirrors, alloy wheels or in-car Wi-Fi hotspot. Or you can spend a lot more to get a loaded Camry with all the fixin's.
Like automakers, antivirus makers hope you'll spring for extra options, whether you need them or not. The one thing you can't trade up to is a bigger engine -- all the Windows antivirus products in a given brand's lineup will use the same malware-detection engine and provide the same level of essential protection.
The basic rung of antivirus software is usually just called "Antivirus" or some variant of that, and list prices for subscriptions are $40-$60 per year per PC. The software will have essential malware protection and possibly a few extra features, such as a password manager or a two-way firewall. Bitdefender Antivirus Plus provides the best bang for the buck at the basic level, with more useful features than rival brands' products.
Midrange antivirus software packages are frequently nameplated as "Internet Security." They generally add parental controls, some of which are very good, plus a few other features such as webcam protection. Midrange packages more likely to come with multi-device licenses than basic antivirus products, and will often include antivirus software for Macs and Android devices. (The iOS "antivirus" apps aren't worth paying for.)
Listed yearly subscription prices for midrange antivirus packages start in the $60-$80 range per machine, but you can pay less if you're patient as online prices will change. Our pick of the litter is Kaspersky Internet Security, which covers multiple platforms and has almost everything you'd want.
At the top of the heap are the premium antivirus "security suites," which toss in all the extra security tools an antivirus brand can offer, such as password managers, VPN client software, backup software, online storage and even identity-protection services. (Not every antivirus brand offers all of these tools.)
The idea is that a premium antivirus suite can be a one-stop shop for all your security needs. List prices for premium packages start at $80-$100 per year, but make sure those extra security tools you'll be paying for are tools you'll actually use. The password managers in security suites are often quite good, but the online storage can be paltry and the VPN services generally don't give you much data before you have to pay for more.
How We Test Antivirus Software
Our evaluations are based on four different criteria: malware protection, performance impact, extra features and ease of use and of installation. How good is the program at detecting and removing malware? How much do scans slow down the computer's performance? Does the program have any additional tools, and are they useful? Can you easily navigate, and easily understand, the program interface? Most antivirus programs have user-friendly interfaces, but we'll ding one if it's too hard to find important tools.
All of our Windows antivirus tests are performed on the same Asus X555LA laptop running the latest mainstream build of 64-bit Windows 10 home, with an Intel Core i3 processor, 6GB of RAM and a 500GB hard drive containing 36GB of files.
To assess a program's impact on system speed, we use our custom OpenOffice benchmark test, which matches 20,000 names and addresses on a spreadsheet. The longer it takes the laptop's CPU to complete the matching task, the heavier the performance impact.
For malware-detection scores, we use the most recent available testing results from four independent testing organizations: AV-TEST in Germany, AV-Comparatives in Austria, SE Labs in England and our own labs in Utah. Each lab regularly subjects the major antivirus brands' products to stress tests involving hundreds of previously unseen pieces of malware and thousands of instances of known malware.
Editors' Note: Why We Still Recommend Kaspersky
Kaspersky antivirus products have been banned from U.S. government networks, which we can understand. Because the company is Russian, using its software would create an unacceptable risk for persons and organizations involved in national security and critical infrastructure.
However, we think Kaspersky software is perfectly safe for home users. We've seen no evidence to convince us otherwise. Kaspersky researchers are well respected throughout the antivirus industry, and the company has publicly exposed Russian cyberespionage campaigns as well as American ones.