Thinking about the amount of havoc-wreaking viruses on the Web is like thinking about the amount of sickness-causing germs circulating within the public transit system. Most people don’t want to know about the scores of viruses waiting to infect their system, but it’s not something you can just actively dismiss if you want to maintain your health and the well-being of your system. Like the common cold silently sifts through the masses unbeknownst, so do worms, Trojans, spyware and the vast slew of other infectious malware that saturate the everyday software landscape and plague your system. Regardless of whether you’re aware of their existence, viruses and other malware often slow application processes and ramp up your CPU usage, while simultaneously modifying integral files and the appearance of your desktop along the way. Catching a virus is tough luck, but thankfully, there’s just as many free antivirus programs to combat the threat of an impending invasion as there are invaders themselves.
Here are our top picks for the best free antivirus software available for both Windows and Mac OS X. Also, check out picks for the best antivirus for Mac if you’re exclusively running Apple’s operating system opposed to Microsoft’s flagship offering.
Updated on 12-5-2013: This article has been updated since it was originally published to reflect recent software changes.
Ad-Aware Free Antivirus+ (Windows)
Lavosoft’s Ad-Aware is one of the most trusted spyware tools and has been a benchmark in the industry for years given it’s incredibly smooth installation, non-intrusive notifications, and fantastic results. The free version of the software provides real-time anti-virus and malware protection in addition to the latest in sandbox emulation technology, thus providing overarching protection whether you’re browsing the Web, downloading files or merely checking your email.
It also features a scheduler, an applaudable addition given Lavosoft’s heavy reliance on user concern and constant updates, and a less-than-intrusive gaming mode for silently blocking pesky malware without the notorious pop-up fanfare that became the staple in the late ’90s. There’s always going to be room for improvement, specifically when referring to the ineffective anti-phishing facet and the program’s subpar rootkit protection, but all of the software’s hallmarks are still there and presented in an impeccably streamlined way that is both attractive and relatively light on your system’s memory. Plus, there isn’t a blatant screen nagging users to upgrade around every corner.
Malwarebytes Anti-Malware Free (Windows)
Much has happened since Malwarebytes first introduced its application back in early 2008. Now boasting a whopping 200 million downloads worldwide (and counting), Malwarebytes offers quite a bit more for the nonexistent price tag. It continues to provide some of the best and most comprehensive virus-removal software available, frequently making it one of the first go-to sources for tech agencies and support groups alike. The program uses Chameleon technology to get the application running on already infected systems, triggering the “mbam-chameleon” app when necessary and helping install and update any required drivers crucial to the software’s functionality. Afterward, the app targets any processes that may have blocked Malwarebytes from running in the first place before scanning for other system threats. Access to the knowledgeable support network and the slew of language options are also an added perk to the free software.
Malwarebytes is the premiere removal-only software on our list, but it’s exclusively removal only; it can’t thwart incoming attacks or provide real-time protection like AVG or Avast can. Although the paid version ($25) opens up options for real-time scanning, scheduling, and increased heuristic updates, the freemium version is more than sufficient in eradicating deeply-entrenched viruses — even when commercial products fail to do so.
Microsoft Windows Defender (Windows)
Microsoft’s innate malware protection has slowly been improving over the years, and we think it’s finally worth a look (albeit briefly). Although Microsoft Windows Defender is enabled by default — offering real-time protection against spyware and pop-ups — it can also be disabled if Windows users want to utilize other defensive programs instead of the one bundled with your PC. The software’s monitoring system recommends actions when urgent attention is required, but interruptions are minimal, helping you stay on task without having to revert to an annoying dialogue box every five minutes.
The software still supports 64-bit platforms, updates virus definitions quickly, and sports a easily-navigable user interface regardless of your operating system. While Defender automatically runs in the background, you can also manually schedule scanning and removal times to a time that’s convenient for you or if you notice something suspicious with your system that leaves you skeptical. Note that software also provides the same level of malware protection as Microsoft Security Essentials, hence the latter is not even compatible with the newer operating system.
AVG AntiVirus Free 2014 (Windows/Mac OS X/Linux/Mobile)
This popular free anti-virus software packs something extra: free anti-spyware protection built right in. The malware detection and removal isn’t as effective a solution as that offered by some of its competitors, such as Malwarebytes, but the spyware detection makes a compelling bonus, especially considering that most anti-virus companies only bundle that functionality into their paid packages. The 2014 edition of the company’s flagship software doesn’t represent a complete overhaul, but the build is more stable and slightly quicker at detecting threats, while ensuring deleted files leave no lingering footprint on your system. Additional tools for filtering incoming and outgoing email are also available, along with components for monitoring network traffic and activating an anti-tracking feature within your default browser.
At $50, the paid version offers a more comprehensive feature set — such as protection for instant messages, downloads, banking, and online shopping — but opting for the premium version is not a necessity if you’re simply looking for an easy-to-use, yet effective, virus protection with a gorgeous grid-based interface to match. Installation can be a chore, and though we aren’t huge fans of banner ads telling us to constantly upgrade to the premium version either, the helpful 24-hour phone support and one-time performance tuneup more than make up for any irksome aspects of the software. It’s also one of the few antivirus utilities to transition to a mobile platform, providing handy tools for remote wiping and locating your Android phone in a pinch.
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