Does Your Computer Have a Virus? Here’s How to Tell

Do you know the signs to look for in case you get a computer virus? These are the things you should check for to make sure your device isn’t compromised.
We may receive compensation from the products and services mentioned in this story, but the opinions are the author's own. Compensation may impact where offers appear. We have not included all available products or offers. Learn more about how we make money and our editorial policies.

Is your computer acting strange lately? Maybe you’ve noticed it isn’t as responsive as it was when you first got it. You’ve tried rebooting, thinking that may solve the problem, but it hasn’t helped.

It’s possible you could have a computer virus. If you do have a computer virus, there’s no need to beat yourself up about it. Most of us have been in this same situation.

With so many viruses created each year, it’s hard to navigate the internet without at least one of them trying to infect your device. Every week, Google finds 50 websites that have malware.[1] Fortunately, there are signs and symptoms you can check and watch for to help you decide if that’s the issue, as well as steps you can take to remove the virus with the best antivirus software.

In this article
Do I have a computer virus?
How to get rid of a computer virus
How to protect your computer from future viruses
How do computers, laptops, and mobile devices get viruses?
Bottom line

Do I have a computer virus?

Some noticeable symptoms usually show up when you have a computer virus. What you experience may vary, given the specific virus, but for the most part, you can count on seeing some familiar signs and a decrease in your computer’s performance.

When checking to see if you have a computer virus, these are the warning signs that will alert you to a problem:

  • Slow device performance

  • Unfamiliar extensions show up on your web browser toolbars

  • You suddenly run out of device memory or disk space

  • Your computer keeps crashing

  • Your antivirus software gets disabled

  • Emails get sent from your account that you didn’t write

  • You get locked out of your device

  • Programs you don’t recognize are on your device

  • Your browser homepage has changed

  • Pop-up windows frequently appear

How to get rid of a computer virus

If you notice the symptoms we’ve mentioned on your device, don’t worry, you have options. There are things you can do to remove the dreaded computer virus from your machine.

You may only need to try one of these steps, but you can use them all if needed. The steps required may depend on the damage done and if you catch the computer virus soon after it infects the device. You can also read our article for more thorough tips on how to get rid of computer viruses.

1. Run an antivirus scan

If you have antivirus software, you should immediately run a full scan of your device. A quick scan saves time when you’re not having problems, but a full scan will be thorough and look through the entire computer.

Computer viruses can be sneaky and they will hide in unexpected places. Recently, cybersecurity experts found that hackers can get malware inside Windows 11 event logs. That makes it harder to detect the virus.

Because computer viruses and malware like ransomware, spyware, and adware are so sneaky, we recommend running a full scan. It is likely to catch a virus that a quick scan could bypass. It may take a few hours, but it is time well spent.

If you don’t have antivirus software, you can still get protection. Some users think it’s too late to get antivirus software after an infection, but you can install it anyway. Once you have it, you can run the full scan.

The 3 best antivirus programs for removing viruses

Not all antivirus software is built the same. After testing dozens of security apps, these three topped our list:

  • McAfee: This antivirus program not only protects you but also helps you prevent future infections on every device in your household. It comes packed with parental controls, a VPN, file shredder, and even identity monitoring.

    See McAfee Plans | Read Our McAfee Review
  • Bitdefender: If you need solid protection against viruses both old and new, Bitdefender offers solid protection. You'll also get access to other tools that help protect your devices, like a VPN, ransomware protection, and a password manager.

    See Bitdefender Plans | Read Our Bitdefender Review
  • TotalAV: If you don't have the budget to pay for antivirus, Avast is a great choice. Its free plan still offers excellent protection with antivirus scans and the Online Security & Privacy browser extension that protects you against phishing attacks.

    See TotalAV Plans | Read Our TotalAV Review

Save $105 on your first year of McAfee+ Premium
Learn More
On McAfee's website

  • All-in-one protection for your personal info and privacy
  • Excellent antivirus protection
  • Additional features like a file shredder and parental controls
  • Multiple pop-ups for text notifications can be annoying

2. Delete infected files

Once your antivirus software finds the computer virus, you need to delete the infection. It may be that you have more than one infected file, so delete them all.

In some cases, users quarantine the files if they think they may need them later. But most people feel safer getting them off their machines.

Saving the file may seem better if you think it’s needed, but only in those cases. Having a quarantined file on your device will take up unneeded space on your hard drive. If you decide to try to clean the file and move it from the safe quarantine location, it could still contain malware if you’re not positive you removed the infection.

3. Get help from a pro

If you’ve tried the steps above and your device still has any of the symptoms given, you may want to contact an expert for help. Many computer professionals have experience with virus removals and can get to the root cause of the issue.

They can also check for any other problems that might be affecting your device. Sometimes a hardware issue could add to the problem, or you could have low memory that makes your computer slow to respond.

How to protect your computer from future viruses

You may have heard the saying that the best defense is a strong offense. That’s a true statement for keeping your device secure as well.

You can take proactive measures to protect your computer from future viruses. For more in-depth tips, you can check out our guide on how to defend against viruses.

You should follow all of these tips to have the most robust computer virus protection. When you use all the tools available, you’re less likely to be the victim of an internet hacker.

1. Update your antivirus

Installing strong antivirus software is important for protecting your device from computer viruses.

You also need to keep your software updated because new malware threats get discovered every day. When you update your antivirus software, you give it a better chance to catch malware because it may recognize the newer viruses.

Make sure your firewall is turned on

If you’re using Microsoft Windows and the Windows Defender firewall, make sure you’ve turned it on. Macs also come with a built-in firewall that needs to be turned on under the Security & Privacy settings.

If your Android, Apple, or Windows device doesn’t come with a firewall, look for security software that includes one.

2. Update your operating system

You may have seen notifications from your operating system that shows an update is available. When you see these notices, go ahead and run the latest update.

Operating systems will release updates that include security patches or fixes. These updates may help protect your device from new malware threats. If you bypass the update, you could miss out on protection from a new computer virus.

3. Use a pop-up blocker

Some operating systems have a pop-up blocker turned on by default. If not, you can select to use it at all times.

You can also disable pop-ups in your browser’s settings menu, including those from sites you once subscribed to that you no longer want to receive communication from.

For instance, if you’re using Google Chrome, you can do this from the three dots in the upper right corner of your browser:

  1. Go to Settings, Privacy and Security, and then Site Settings.
  2. Select Site Settings, then Pop-ups and redirects.
  3. Make sure the toggle is moved to block pop-ups.

Total Adblock's browser extension makes it easy to see how many ads it's blocked as well as toggle it on and off.

That’s how easy it can be to block these unwanted ads, but if you want a stronger ad blocker, we recommend a third-party app like Total Adblock.

We Recommend Total Adblock to Get Rid of Pop-Ups
Learn More
On Total Adblock's website

Total Adblock
  • Remove ads & trackers on YouTube, Facebook, and most websites
  • Hands-off ad-blocking experience
  • Easy to set up
  • Free version excludes top 15,000 websites

4. Don’t use third-party apps

When you use third-party apps, you could download a computer virus.

A third-party app is one you get from a website rather than your operating system’s app store. If you choose to use a third-party app anyway, read reviews online from other users to make sure they haven’t experienced viral issues with the application before you download it to your device.

5. Don't click on suspicious links

A common tactic hackers like to use to infect your computer is to send you a link that looks like it leads to a legitimate site. This is called phishing, and you could find these malicious links on social media, in an unexpected pop-up ad, or even in an email. 

Malicious links could even come from a trusted person, like a friend or family member, if they're using an infected computer. If someone you know sends you an odd-looking link with no context and it seems out of the norm, don't click.

If you're ever in doubt about a link, try Googling the website you're looking for instead of clicking. You can also hover your cursor over a link to see the URL of the website it will take you to. 

Watch out for link typos too

Phishing scams might even try to fool you into clicking on a bad link that goes to a site that, at first glance, looks like the real thing. As an example, a hacker could try to fool you into clicking on a link for when you really want to go to

6. Run frequent virus scans

One way to prevent future computer viruses is to run frequent virus scans.

You don’t have to run a full scan every day. You can run a quick scan once a week to make sure your device doesn’t have any suspicious files or programs.

If your antivirus or anti-malware software does find something, delete it. You don’t want something you don’t recognize hanging around on your device that could cause trouble later.

How do computers, laptops, and mobile devices get viruses?

Computer viruses don’t simply appear on your device. The malware must get accessed in some way, such as by email attachments, external storage devices, or downloads. Viruses can also spread through networks where devices are connected.

Many times, you could download software and not know it contains a hidden computer virus. If you connect an external hard drive or other removable media, you could easily infect your machine with a virus. In 2010, the Conficker worm spread through the use of flash drives and cost over $9 billion.



What are the symptoms of computer viruses?

The symptoms of computer viruses can include the following: 

  • Frequent crashing
  • Performance issues
  • Unrecognized programs on your device

You may also find yourself locked out of your device.


What do I do if my computer has a virus?

If your computer has a virus, you should take steps to remove it immediately, including running a full antivirus scan that can usually look for more hiding places than a quick scan.


How do I know if my computer was hacked?

One of the signs that your computer got hacked is seeing emails sent from your account that you didn’t send. 

In more severe cases, you could have sensitive data stolen, like banking information. Sometimes the bank may call you to verify spending. Other times, you may see your credit score drop and not understand why until you check into it.

Bottom line

A computer virus makes your device act sluggish, much like your body might when you have a virus. Your device won’t be as fast to open programs and web pages. You may also notice it freezes and crashes in the middle of working.

If you suspect your device has been infected with a computer virus, it’s crucial to get the virus removed as soon as possible. The longer it stays on your machine, the more damage it can do. One of the best tools you can utilize to protect your device is good antivirus software.

There are software choices for every budget and need. Many antivirus programs let you customize your software to get the most bang for your buck. Check out our recommendations on the best antivirus programs to keep your data safe.

Save $105 on your first year of McAfee+ Premium
Learn More
On McAfee's website

  • All-in-one protection for your personal info and privacy
  • Excellent antivirus protection
  • Additional features like a file shredder and parental controls
  • Multiple pop-ups for text notifications can be annoying

Author Details
Patti Croft is a freelance writer who specializes in all things technology. Her expertise includes antivirus software, online security strategies, and safety practices. She has a degree in Computer Information Systems and extensive experience working in the IT field. In her spare time, Patti is an avid reader and researcher, and loves spending time with her pets. She currently shares an office with her cat, Beau.


[1] A Not-So-Common Cold: Malware Statistics in 2023