The 5 Best Free Antivirus Software of 2017

Protect your Windows computer with a free antivirus program

Illustration representing malware moving from one computer to another
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A good antivirus program is essential to a secure system, and you most definitely do not have to pay for one to get great protection. Below is our hand-picked list of the five best free antivirus programs that you can download for Windows today.

All of these programs perform definition updates automatically, are always running to make sure your files are protected from malware and your personal information remains private, and can start scans on-demand whenever you like.

However, each of them do have a few prominent differences that make them stand out, so pay attention to those as you decide which one to use.

Note: If you just need a spyware cleaner, and need it right now without waiting for one of these full AV programs to install, use one of the (preferably portable) applications from our Best Free Spyware Removal Tools list. Also consider installing a Windows Firewall alternative from this list of Free Firewall Programs.

If you're looking for protection on your other devices, check out our list of free antivirus apps for Android and best Mac antivirus articles too.

Important: If you can't even log in to Windows to install an antivirus tool, access a computer that does work and then use it to make a free bootable antivirus tool that you can then run on the infected computer.

Screenshot of Avira Free Antivirus in Windows 10
Avira Free Antivirus.

The main component in Avira's free software suite that makes it stand out is the optional "in-the-cloud detection" feature called Protection Cloud. This scanning method lets Avira's antivirus tool identify and stop threats before they get out of hand.

This is how it works: When a suspicious file is detected on any computer running Avira, a fingerprint of that specific file is generated and uploaded anonymously to Avira so that they can scan it and report its status (whether it's safe or dangerous) back to every Avira user so that the program can take appropriate action. 

Avira can scan and remove existing threats as well as automatically detect and stop new ones. It protects you against ransomware, Trojans, spyware, and other kinds of malware. You can even choose which ones to actively watch out for, and disable others (though it's not recommended) like dialers, jokes, adware, etc.

Avira Free Antivirus can also:

  • Scan on a schedule
  • Check files with any file extension or just the ones you manually choose from
  • Disable the ability to stop active scans (so that viruses can not stop the program from finding them)
  • Adjust the scanner's priority level
  • Scan master boot sectors
  • Follow symbolic links to scan the actual files
  • Search for rootkits before starting a scan
  • Scan the Windows Registry
  • Ignore files on network drives
  • Automatically repair, rename, quarantine, delete, or ignore threats when they're found
  • Use heuristic scanning
  • Add files, folders, and processes to the ignore list
  • Manage Windows Firewall settings
  • Password protect the program's settings
  • Block auto-run on removable devices
  • Make the hosts file read-only

Download Avira Free Security Suite

The Avira suite offers more than just a very extensive antivirus application. It includes several other "layers" of security that will install automatically, and they might take a while to download since there are several. However, you don't have to use them and they won't bother you unless you open them.

These separate modules include a VPN that encrypts all your traffic (up through the first 500 MB each month); password manager to securely store complex passwords; and software updater that identifies outdated programs and gives you the download links to update them. 

In addition to those, Avira can speed up your computer and reduce boot up time with its tune-up tool, help you find the best deals as you shop online, and warn you of malicious websites or software bundles before you download them (with its SafeSearch add-on).

These extra features can be annoying if you're strictly after an antivirus solution, but again, you don't have to use them; just keep them tucked away where they are and you won't have to worry about them.

Avira Free Security Suite is intended to run on computers with Windows 7 SP1 and newer, including Windows 10 and Windows 8. More »

Screenshot of Bitdefender Antivirus Free Edition in Windows 10
Bitdefender Antivirus Free Edition.

If you want an antivirus program that's not only free but super easy to use and not cluttered with lots of buttons and menus, you should definitely try the free version of Bitdefender Antivirus. 

You not only get instant protection against viruses, worms, rootkits, spyware, etc., but also anti-phishing and anti-fraud protection to carry security with you when you're browsing the internet and entering passwords.

It's actually remarkable how well Bitdefender runs despite its minimal design. You can drag and drop folders and files directly into the program to instantly run a scan against them, as well as immediately start a full system scan or scan select objects from the right-click context menu - all of which can run at the same time.

Regardless of how they're started or how many scans are running simultaneously, a history of those scans are recorded for you on the primary window of the program as well as within the Events area of the settings. 

Download Bitdefender Antivirus Free Edition

The obvious downside to a program that lacks many customization options is that there isn't much you can change about it. That might be something you want but it might not be; so be aware that basically all you can do with this edition of Bitdefender is start and stop scans.

Another downside to this software is how long it takes to become ready for you to use. The initial installer for Bitdefender is quite small but that's just what's used to then download the full program, which is hundreds of megabytes and could take a while if you have a slow internet connection. 

It's also unfortunate that you can't pause scans (it just lets you stop them) or set up file and folder exclusions before starting scans like some AV programs allow. With Bitdefender, you can only mark files or websites as safe after they've been identified as malicious.

Ads asking you to purchase Bitdefender's professional programs and scheduled scans being supported (but they're not necessarily needed since Bitdefender is always checking for new threats) are a few other not-so-greats.

Bitdefender Antivirus Free Edition runs on Windows 10, Windows 8, and Windows 7. More »

Screenshot of Adaware Antivirus Free in Windows 10
Adaware Antivirus Free.

Adaware Antivirus installs in minutes, is light on system resources, and can be used in one of two ways. The first is in regular mode where it checks for threats as they happen, but the other lets you use it in addition to your "main" antivirus program (i.e. along with Bitdefender or Avira,). 

What this so-called "second line of defense" does is disables real-time protection but still lets you use Adaware Antivirus to manually scan for existing threats. This is helpful if your primary AV software doesn't seem to find malware that you know is infecting your computer.

Whichever way you use it, Adaware Antivirus provides a defense against ransomware, spyware, viruses, and other forms of malicious software. You can find those threats through a quick, full, or custom scan.

Daily, weekly, and monthly scheduled scans are supported, and you can even run a scan to just check certain things, like only rootkits or just tracking cookies and boot sectors, for example.

Adaware Antivirus also lets you choose a custom performance setting to use more system resources to run the scan (to make it faster), exclude files/folders/file extensions from scans, and decide how often to check for new definition updates (every 1/3/6/12/24 hours).

When it comes to real-time protection, you can toggle on or off the following options:

  • Scan archive files
  • Scan email databases
  • Deep scan that checks CHM files and executable files
  • Smart scan that skips previously checked files
  • Scan boot sectors
  • Scan files as they move throughout the network
  • Skip scanning files that exceed a custom file size (e.g. 10 MB to skip video files, etc.)

You can also protect the program's settings with a PIN as well as enable gaming/silent mode to suppress notifications.

Download Adaware Antivirus Free

Adware Antivirus definitely has its advantages but because there's also a non-free version you can upgrade to, many additional options are not supported.

For example, parental controls and advanced network, web, and email protection are only available in Adaware Antivirus Pro.

These options are visible within the free edition but they're not actually clickable/usable until you enter an Adaware Antivirus Pro license key.

Adaware Antivirus Free works with all versions of Windows. More »

Screenshot of Avast Free Antivirus in Windows 8
Avast Free Antivirus.

Avast is used by hundreds of millions of people and ranks high in nearly every "best list" of antivirus programs, and for good reason. If you want a solid program that is sure to block new threats but is still easy enough to customize, you should consider using it.

Avast Free Antivirus is similar to Avira which we mention above; there are numerous components that you can install along with the virus shield that provide additional services related to security and privacy (more on those below).

The antivirus portion has lots of options you can change but it's still easy enough for anyone to use since there are information blurbs next to most items so you're not left wondering what will happen if you enable them.

Plus, both definition and program updates are performed automatically (a manual option is available too), meaning you can install Avast and let it do it's thing without worrying whether you're running the latest and greatest version.

Avast is highly customizable and lets you make changes to everything from whether to make a sound when threats are detected and how long notifications should remain on the screen, to the kinds of file extensions that should be scanned.

Here are some more features supported in Avast Free Antivirus:

  • Scheduled scans
  • Custom scans that can check only the memory, rootkits, auto-start programs, etc.
  • Checking all files or just certain file extensions
  • Identifying files by their content instead of their suffix
  • Fine-tuned heuristics sensitivity
  • Scanning for potentially unwanted programs
  • Follows shortcuts to scan the real file
  • Can scan within lots of archive file formats like self-extracting DOS and Win32 executables, CHM, ACE, 7Z, RAR, TNEF streams, Mac archives, ISO, and more
  • Windows Explorer context menu integration
  • Folders, HDDs, and URLs (but not specific files) can be pe-excluded from scans
  • Custom scans are easy to save for use in the future
  • A Rescue Disk can be created that lets you use the Avast scanner even if you can't start your computer
  • Particular areas of the program can be protected with a password

Download Avast Free Antivirus

Before Avast is installed, you have the option to include over a dozen different tools: file, behavior, web, and mail shields; software updater, browser cleaner, rescue disk, Wi-Fi inspector, security and SafePrice browser extensions; VPN client; password manager; junk file cleaner; and Game Mode.

Technically, if you only want the antimalware protection, you can install just the shields from the start of that list; the others are add-ons that aren't necessary but could be helpful at some point.

For example, the software updater is a nice tool that will not only check for and report outdated software, but also install the newer versions for you (even in bulk). This is a great way to make sure your programs are up-to-date with their latest security patches and features.

Wi-Fi Inspector scans the network for devices that could be vulnerable to attacks. For instance, it might identify that a computer is running a file sharing service that has been known to facilitate the spread of a certain kind of worm.

You can install these tools (it takes less than five minutes) and then disable or completely remove them later. Or, you can ignore them during setup and just install them later, or not at all.

However, please know that the password manager, SecureLine VPN, and Cleanup tools are only trial versions that will expire after so-many days. There's also a firewall, file shredder, and sandbox feature that's unusable in this free version.

Avast Free Antivirus is compatible with Windows 10, 8, 7, Vista, and XP. More »

Screenshot of Panda Free Antivirus in Windows 10
Panda Free Antivirus.

Panda Security's free antivirus program installs in minutes and has a minimal design like Bitdefender, mentioned above. However, even though it's not a CPU or memory hog, and doesn't appear to be customizable, all of its many options are tucked away in the settings.

From there, you can do things like set up both on-demand and automatic scans to check compressed files and scan for potentially unwanted programs.

The automatic, permanent scanner includes some additional options too, like behavioral and analysis scanning options, the ability to ask you before neutralizing a virus, and blocking files from running for so-many seconds until results on whether it's safe or harmful are obtained from the cloud.

Something entirely unique to Panda is its security news and alerts sections that can show you critical, warning, and informational messages like when a popular vendor experiences a data breach that could affect your personal information. You can, however, turn those off if you want to.

You can complete a scan in just a few minutes if you only want to check for actively running threats, like browser cookies, processes, and things currently loaded in memory. However, there's also of course an option for a full system scan or a custom scan.

Here are some other things you can do with Panda:

  • Password protect the entire application
  • Have the quarantine emptied every three days, every week, every month, or never
  • A gaming/multimedia option will disable all notifications if you're using a full screen application
  • Exclude particular files or folders from scans, as well as specific file extensions of your choosing
  • USB protection can be enabled to always scan removable devices as they're attached, to make sure that they don't spread anything to the computer
  • Monitor running processes as well as any URLs accessed by them, and have them terminated if Panda deems them a threat
  • Record everything in event reports that you can browse through and even print or export to a TXT or CSV file
  • Can optionally install Panda Safe Web during setup to protect you against malicious websites

Download Panda Free Antivirus

The Panda antivirus software does a really good job at keeping the important buttons up front and hiding the additional options within menus so that you're not constantly bombarded with options or alerts.

However, the program will change your home page and the search provider in your web browser, unless you uncheck those options during the initial setup.

Panda Free Antivirus works in all versions of Windows from Windows 10 back through Windows XP. More »

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