How to get rid of computer viruses and malware

Nobody wants to deal with a virus, ransomware, or other kinds of malware on their computers. Depending on the complexity and depth of the infection, it may render a computer unusable, or it may just slow down a device.

Whatever the malware does, it’s best to have it purged from your device. Thankfully, a computer virus, ransomware, or other malware infection doesn’t mean you have to rush out and buy a new device. You can cleanse it instead.

If you’re reading this page, you’re likely dealing with an infected device. But if you’re not, or you’ve followed the steps below to cleanse an infected device, it’s important to understand that the best defence against viruses and malware comes before infection.

These days, there are a range of reliable software choices for some of the best antivirus and anti-malware software including two of our best picks, Bitdefender and Norton. You can even take advantage of viable real-time threat protection from some of the best free antivirus and anti-malware programs. It’s important to have antivirus and anti-malware software installed on a computer—particularly PCs which tend to be targeted more than Macs—and to keep them up-to-date.

Get into the habit of running regular manual scans for threats and, where possible, set antivirus and anti-malware software to automatically update and run regular automatic scans. Be wary of what you download on public Wi-Fi, and  any files you download, particularly email attachments. Additionally, keep your computer’s operating system and software up to date, as patches tend to include security updates. Regular backup of critical files is also recommended, including work documents, personal files, and photographs.

You may not know your computer is infected with malware, which is why regular scans are important. While it’s advised that you only have one kind of antivirus software installed—after all, a good one should get rid of malware and protect from viruses—you can optionally install anti-malware software outside of your main antivirus program. If you suspect your device is infected with malware, follow these steps:

1. Download and install antivirus from a reputable provider.
2. Manually update the antivirus software (if available).
3. Run a scan. We recommend a deep scan over a quick scan (the latter is more useful for upkeep than infections).
4. After the scan completes, follows the cleansing steps recommended by the antivirus software.

If you have additional anti-malware installed alongside your antivirus software—including popular options like Malwarebytes, CCleaner, and SpyBot (all of which have free versions)—we advise running them after an antivirus deep scan. They may not find any additional malware, which is a good sign you’re using great antivirus, but they do offer additional features like registry cleaning (CCleaner) and immunisation (SpyBot).

While malware might not have a noticeable impact on your computer, viruses tend to be more severe. You’ll know you have a virus if computer performance noticeably slows, you have pop-ups prompting you to install software or even to clean your computer (that aren’t from your antivirus provider), or programs you didn’t install are running in the foreground or background. Depending on the severity of the virus, you may not be able to access your device at all.

Follow these steps for the most thorough virus removal:

1. Download and install antivirus from a reputable provider.
2. Manually update the antivirus software (if available).
3. Disconnect from the internet, either by temporarily disabling WiFi or disconnecting an Ethernet cable from your device.
4. Restart your computer and enter ‘safe mode’. For Mac, press and hold the Shift key during restart until you see the login screen. On recent versions of Windows, hold Shift while selecting ‘Restart’ to enter safe mode. On the blue Windows start-up screen, select ‘Troubleshoot’, ‘Startup Settings’, then ‘Enable Safe Mode’.
5. If a virus has locked you out of your Windows PC, hold down the power button to turn it off. Power back on, then hold down the power button once you see something on the main screen. Repeat this twice more, then wait for the ‘Preparing Automatic Repair’ prompt on the next restart. Follow the same blue start-up steps above to restart in safe mode.
6. On Windows PCs, press the Windows key and type ‘disk’ then open the ‘Disk Clean-up’ result. Select the C drive to clean, click ‘OK’, then accept the pop-up message to remove temporary files.
7. On Windows or Mac computers, run your antivirus and/or separate anti-malware software with a deep scan in safe mode.
8. Once the scan completes, follow any recommended steps from the antivirus software.
9. Restart your computer normally, connect to the internet, then run another scan to see if your antivirus software picks up any additional virus or malware files.

If your computer is infected to a degree that makes it difficult to use, disconnect the computer from your network to limit the spread of infection. Now find another compatible device to download software to and get a USB drive ready. Download antivirus software onto the USB drive on the other device—Malwarebytes Free is a great place to start for fully infected devices—then connect the USB drive to the infected computer that’s disconnected from your local network.

Start the device in safe mode, log in, and install the antivirus software. Run a full scan in safe mode to get rid of viruses and malware. Restart the computer normally to confirm you can properly access your machine again. If you can, reconnect it to your network, update the antivirus software, and run another scan. It’s also advised to run a scan on the USB drive before connecting it to any other devices in case it was infected, too.

Viruses used to be the biggest threat you could encounter on computers, and while they’re still a painful reality, ransomware is arguably a far scarier threat these days. You’ll know your computer is infected with ransomware because your personal files will be locked, sometimes with different extension names from typical files. Attempting to open locked files will, instead, result in a ransom message, demanding payment to unlock your files. Alternatively, there may be a more obvious pop-up message demanding payment without you trying to unlock personal files.

Follow these steps to remove ransomware:

1. Disconnect your device from the internet to avoid the ransomware from spreading across your network or to cloud storage. Also disconnect any external hard drives.
2. Visit the No More Ransom website on another device. This website is an antivirus industry initiative that offers free unlock tools for infected devices. Identify the type of ransomware, then download the corresponding unlock tool, copy it to a USB drive, and follow the installation guides.
3. Unfortunately, not every type of ransomware has a free solution available, though the No More Ransom website will update as new unlock tools are created. If your computer is infected with a different kind of ransomware, contact a computer specialist for assistance.
4. Contact an antivirus provider that promotes its anti-ransomware capabilities (like Kaspersky) and talk about your options for cleansing and unlocking the infected computer.
5. If all else fails, reset your device and restore uninfected personal files from a recent backup.