I think my computer has a virus


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I think my computer has a virus

Man stands next to his window in the house while looking at his tablet

What's coming up?

If your computer starts acting strangely, it may have contracted a virus from a file you've downloaded, either through a website or an email.

In this activity, we're going to look at the process of identifying and dealing with a virus.

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Signs of a computer virus

How do you know your computer has a virus? There are some common signs to look for:

  • A message on the screen says that files have been locked and you need to pay to unlock them.
  • Some programs won't start.
  • Websites open when you don't want them to.
  • Ads popup and cover your computer screen.
  • Your computer runs very slowly.

Not all of these are certain signs of a virus. But you can still check by running a virus scan. We'll look at this in the next panel.

A pop-up message from antivirus software warning that a virus has been detected on a computer
An example of an antivirus scanner menu

Step 1 - Run a virus scan

If you think that you may have a virus, the first thing you can do is run a virus scan.

If you have installed antivirus software, you can use it to run a scan of your computer. Unless the virus is very new, the software should be able to detect and remove it.

If you are unfamiliar with antivirus software, you can find out more in our What is antivirus software? activity in the Downloading and saving documents course.

Running a virus scan

Mary is worried that she has contracted a virus on her computer. She is going to do a scan of her computer using an antivirus program from the internet.

Click Continue to watch the video on the next screen.

Running a virus scan

This video is approximately 1 minute and 8 seconds in duration. It demonstrates how to run an Avast! virus scan.

Once the video starts, the intro panel fades and we see the screen is split into two parts. On the left-hand side is a close up of Mary's computer showing the icon for her Avast free antivirus software. On the right-hand side, there is text displayed, which is the script for the voiceover track.

Voiceover: "To run a virus scan, Mary first starts her computer’s antivirus program by double-clicking the icon on her desktop."

The left-hand panel shows the cursor move up the screen and double-click on the Avast icon to open the software program. The screen then pans out to show the Avast software page opening with a large green button saying Run Smart Scan. The cursor clicks on this green button and the software starts its scan.

Voiceover: "To start scanning for viruses and other threats, Mary clicks on the Run Smart Scan button."

The left-hand panel shows the progress % graphic start to swirl on the left-hand side of the screen as the scan starts.

Voiceover: "The program takes a while to scan, but Mary can do other things while it works. She chooses to browse the internet while she waits. But she could also choose to leave her computer to finish the scan, and return to it later."

The left-hand panel shows Mary click away from the Avast page and open up her Google search page. She types in the word Dalmatians to search on, and we see a Wikipedia page all about dalmatians open up. Mary quite likes Dalmatians! After reading a bit about dalmatians, Mary checks back on the scan by clicking back to the scan page. She sees it has already progressed to 83%.

Voiceover: "If the program finds a virus, it will ask Mary if she’d like to fix the problem. If no viruses are found, it will give her the all clear when it’s done. It is important to scan and remove viruses from your computer often to stay safer online."

Video ends.

Step 2 - Call the antivirus help line

If you subscribe to an antivirus software program, the subscription may include phone support. (You should check when you subscribe, and make a note of the phone number.)

Call the antivirus software company’s help line, and they may be able to walk you through a remedy.

A phone icon with the antivirus shield representing the antivirus hotline
A graphic with tool symbols on it representing tech support

Step 3 - Call computer support

If you don't subscribe to an antivirus program, you may have to call in help. If you have a computer-savvy relative, they can be a good first point of call.

Otherwise you might have to contact a computer help service to help fix the problem. There are thousands of such services all across the country, and a search of the internet or of the phone book should find one near you.


You've completed the I think my computer has a virus activity.

Viruses can be tricky, especially because it's not always clear that you have one. But if you think there's a problem with your computer, and you think a virus might be the cause, there are clear steps you can take to check:

  • Run an antivirus scan.
  • Call an antivirus hotline.
  • Call trusted technical support.

In the next activity, I think somebody has access to my passwords, we look at what to do if you think your password has been stolen.

A couple look at their computer screen while enjoying a cup of tea at home