Antivirus alone or security suite? Antivirus software comes as a stand-alone program, but you can also purchase it as part of a comprehensive security suite. Security suites, covered in our separate report on Internet security software, are more expensive, but they include a range of protections, including antivirus, anti-spyware and anti-spam programs, identity-theft protection, firewalls and parental controls. If you opt for an antivirus program that doesn't include these features, experts recommend supplementing it with other components, especially a firewall and anti-spyware software.
Check the system requirements. Make sure the antivirus program you choose will work with your Windows or Mac operating system. If you have an older computer, a large antivirus software program can consume a huge percentage of your computing power and you may run into compatibility problems.
Avoid conflicts. Antivirus software rarely plays nicely with similar products from different vendors. Before installing software from another company, completely uninstall any pre-existing security software. That holds true for the antivirus software provided as part of Windows; Microsoft recommends that you uninstall Windows Defender (Windows 8 or later) or Microsoft Security Essentials (Windows 7 or earlier) before installing any third-party antivirus program.
Mac owners: Find out what's covered. Many antivirus programs don't provide as many (or any) products or features for Mac users. Some multi-device software suites have limitations for Apple products but are upgrading their features constantly. Mac users should be vigilant about understanding what they're getting before they pay; discuss the issue with customer service if the information on the company's websites is unclear. This is particularly true of multi-device software suites.
How many licenses do you need? Antivirus software is sold in versions that cover a single product, or up to 10 or more. Multi-computer licenses are generally cheaper on a pre-device basis, but that isn't always true, so be careful not to overbuy. Prices vary widely, so shop around.
Antivirus software is a recurring expense. Most antivirus programs provide updates only for one year, so be prepared to pay annual renewal fees.
Don't expect free telephone support, especially with free software. Although some antivirus programs come with free telephone support, it is rare to find this feature with free software. Even online or chat support isn't guaranteed with free products.
With paid antivirus software, start with a free trial. AV-Comparatives.org recommends downloading a free trial of your chosen antivirus software to ensure you like how it works. Most companies offer at least a 30-day free trial.