Microsoft Windows has come with it’s own antivirus for quite some time. Windows 10 and 11, for example, came with Windows Defender built in and on automatically unless another antivirus was installed, at which point it would automatically switch off. Windows Defender by itself is plenty of defense for the kind of run-of-the-mill threats you’d run across browsing unsecured websites or trying to download games from websites other than big, trusted ones like Steam (given you’re listening to it when it suggests you double-check the source and double-check that you meant to download a .exe file) but some people would rather have this protection from a paid-for antivirus like Kaspersky or McAfee. The fact that those programs cost money doesn’t necessarily mean they’re better, but it can be a peace of mind thing – complaining about something that cost money means that some penalty can be extracted if the user isn’t satisfied, even a penalty as small as a partial refund.
This Computer’s Not Big Enough for the Two of Us
Windows Antivirus is unique for automatically stepping down when another program steps up. Many others don’t!
Antiviruses do not get better the more that you have. They interact in ways that step on each other’s toes and lead to false alarms. As an example: say a computer has both Norton antivirus and McAfee antivirus installed. McAfee will try to scan the computer for new threats upon startup, but will be interrupted by Norton, who interprets the file-checking as potentially hazardous behavior. Norton isn’t wrong, because ransomware will often sweep through files in some way or another, but it doesn’t recognize McAfee, and almost no other program has a reason to do that anti-viral scanning. Thus, Norton then tries to report McAfee to you! Some antiviruses have safety rails that literally will not let you whitelist (whitelisting refers to telling a program that a file or action is okay, or ‘whitelisted’) certain executable programs, so you get stuck in this horrid, unbreakable loop of antivirus fingerpointing every time you boot up your computer.
These interactions actually make your computer less safe – if both antiviruses have deadlocked themselves out of scanning because the other one says it’s a virus, your computer is not being scanned. That’s bad! Scanning is not completely foolproof, and a regular residential antivirus won’t necessarily be able to catch or handle something industrial grade, but it catches plenty of small things like trojans before they become serious problems that can cripple your computer.
Your computer is much better off with just one brand of antivirus on it at a time. Instead of more, buy better. And if you’re unsatisfied with one brand’s performance, completely uninstall it before you install the program you replace it with. Not only does that prevent them from interacting in a negative way, it also prevents the previous program from hassling you to renew it with pop-ups (McAfee is infamous for this). Either way, it’s going to save you some annoyances!
And in Other Realms
The antivirus problem is a pretty unique one because most programs don’t interact with every file on your computer in the way that they do. Two art programs are not going to start fighting over which one you should use, for instance. However, some other cases can be pretty similar. Like VPNs! Having more VPNs is going to slow down your computer without much additional benefit. The way a VPN works is that it takes your request, encrypts it, sends it to a server, unencrypts it, completes the request, encrypts it again, and then sends it back to you. This keeps your ISP from seeing this request, but it doesn’t necessarily anonymize the data – after all, the VPN’s server has to unencrypt the data to actually complete the request, so the VPN knows what the data is, and it knows where the request is coming from in the first place. The VPN has the same visibility the ISP initially had. Adding more VPNs to your computer will not solve this problem, it will just move it down the chain, and add extra time to each request you make in the meantime as it bounces around VPN servers.
If you only need to protect your data from the coffee shop’s open Wifi or want to watch Netflix Canada, the kind of VPNs you see advertised on Youtube will be able to do the job – the data won’t be strictly, unsubpoenably anonymous, but it will be encrypted and rerouted well enough to make those two things happen. If you’re trying to search for things that nobody can know about, you’d be better off downloading TOR (which stands for The Onion Router), a popular VPN with an excellent reputation for encryption and security. Using TOR to do illegal things is illegal, of course, but the act of downloading it and using it by itself is not.