Computer viruses are small, harmful pieces of software that trigger all kinds of unpleasant behavior on your computer. Viruses spread from computer to computer by diverting resources from host machines in order to replicate and reproduce themselves, much like biological viruses do from person to person. A virus, if present on your computer, can change the behavior of certain programs or functions to help it replicate.

Some viruses are relatively harmless, but others can cause long-term damage. The good news is that virus infections can be cured. You can even try to correct problems caused by viruses yourself and attempt to remove them.

What is the difference between a virus and malware?

We hear a lot of talk about “virus” and “malware” as if they are the same thing, but they are not. This confusion is especially problematic if you are trying to remove malware that is not a virus. So let’s clarify the differences between viruses and malware.

Malware is an umbrella term for all types of malicious software, i.e. all programs or code designed to cause harm. Viruses are just one of the many types of malware out there. All viruses are malware, but not all malware is a virus.

If you need to remove malware, the process may vary depending on the type of malicious code. It is therefore important to understand this distinction if you want to remove viruses from your computer.

How to remove a virus from a PC

Now is the time. If your computer is infected, we will see how to eliminate all the viruses on it and get it back to working order. The most reliable technique for removing malware such as viruses is to use a dedicated virus removal tool. This tool scans your computer and checks it for traces of infection, so you don’t need to worry about how to remove viruses yourself.

In this article, we’ll show you how to remove malware from Windows 10, knowing that these same principles also apply to older versions. First, a quick note: outdated software presents security risks, as updates and patches often eliminate vulnerabilities security present in earlier versions. If you connect your computer to the Internet, the software it uses must be up to date.

Let’s go! Let’s see how to get rid of viruses on a PC.

1. Open safe mode on your PC

You must first restart in safe mode, which limits your computer to operations that it absolutely needs to function. This is useful when you remove viruses from your computer, the infected files are then disabled.

Depending on the level of computer access you have, you can apply safe mode in different ways:

Option 1: Open safe mode from settings menu

Press Windows + I to open the Settings menu. You can also open the Settings menu by opening the Start menu, then scrolling down to Settings.

Select the Update & Security category. You may need to scroll down to find it.

In Update & Security settings, select Recovery, then click Restart Now under the Advanced Startup category.

Your computer will restart and display the Choose an option screen. You can tell Windows 10 how you want it to start. Go to Troubleshooting > Advanced Options > Startup Settings > Restart.

After restarting again, you will see a list of options for loading the operating system. Select 4 or press F4 to boot into safe mode.

Option 2: Open safe mode on login screen

If you can’t log in to your computer, you can restart it in safe mode from the login screen. On this screen, hold down the Shift key while clicking the Power icon, then select Restart.

Your computer will restart and automatically open the Choose an option screen. From there, you can follow the procedure described in the previous step.

Option 3: Open safe mode by shutting down your computer

If your computer is unusable, force shut down by pressing and holding the power button for 10 seconds. Once it shuts down, restart it normally by pressing the power button. As soon as the computer gives sign of life (by a startup sound or an on-screen logo), press the power button for 10 seconds to shut down your computer. Repeat this shutdown/startup process one more time.

The third time you turn your computer back on, let it fully boot up and enter WinRE (Windows Recovery Environment) mode. Then follow the same steps in the Choose an option screen to select Safe Mode, as explained above in option 1.

2. Delete temporary files

Once in safe mode, run disk cleanup to remove all temporary files from your computer. Reducing the number of files on your computer will speed up the virus scan that you will perform in the next step. If you’re lucky, you may have already eliminated the malware from your system at this point and you won’t need to go any further.

1. First, open the Start menu and select Control Panel from the Windows System drop-down menu.

2. Select Administrative Tools.

3. Open Disk Cleanup from the list of tools.

4. Check the box next to the file types you want to delete. We advise you to delete all temporary files and empty the trash. If there are any remaining items that your system doesn’t use, delete those too.

5. After making your choices, click OK. Then click Delete Files to confirm.

3. Perform a system virus scan

Once the temporary files issue has been resolved, you are ready to use a trusted cybersecurity tool to scan your device for signs of computer viruses. Avast One performs a deep scan of your device for viruses, malware and other threats to your security and privacy. To protect your PC, all you have to do is solve the detected problems with a single click. We continuously update our anti-virus software to protect you from the latest threats as they emerge.

Now all you have to do is let Avast One (or antivirus app of your choice) do its job. Since you’re in safe mode, you won’t be able to open Avast One normally (it continues to keep your computer safe). We’ll show you how to set up a safe mode startup scan before you restart your computer. This will allow Avast One to scan your computer when it restarts for malware.

1. Press the Windows + R keys to open the Run dialog box. Type cmd, then press Enter to open the command prompt.

2. In the Command Prompt window, type CD, followed by the location of the Avast installation file. The default location is C:\Program Files\Avast Software\Avast. Then press the Enter key.

3. To schedule a startup scan of all disks on your PC, type sched /A:*, then press the Enter key.

4. Command Prompt should confirm startup scan with “Scheduled”. After this confirmation, type shutdown /r and press the Enter key to restart your computer and run the startup scan.

5. When your computer restarts, Avast One performs a startup scan to check for viruses and other malware. This may take a few minutes.

6. Once the scan is complete, the computer completes the boot sequence.

4. Recover damaged software and data

Your cybersecurity tool can tell you if a file is a virus and how to remove a virus from a file without deleting it. However, many viruses can damage your software and files. You can try restoring them from a backup copy.

Note that you must have Windows Backup Tools enabled beforehand to be able to use them at this point.

Use backup files

If you don’t make regular backups of your important files, it’s time to get started. Having an up-to-date backup on an external hard drive or in the cloud is the best protection against viruses (apart from anti-virus software, of course).

Here’s how to restore your files from a backup copy in Windows 10:

1. Open the Control Panel via the Start menu at the bottom left of your screen.

2. Choose Backup and Restore (Windows 7) in the System and Security section.

3. If you have already created backups, you will find them here. Click Restore my files to recover your files.

4. Then choose the files to restore from your backup. You can restore the entire backup by selecting Browse Folders.

5. Select your backup and click Add Folder.

6. You will see your backup in the list of files and folders you are going to restore. Click Next to continue.

7. Tell Windows where to put the restored files. If you want to restore things to exactly the way they were, select In Original Location, then click Restore.

8. If Windows detects that the original files are still on your computer, you can choose to replace them or leave them intact. Select Copy and Replace to ensure that you recover all your files in good condition. At the bottom of the window, check the box next to “Apply my choices to all conflicts” to replace all duplicate files.

9. When the restore is complete, click Finish to end the process. Your files and folders are now free of all viruses.

How to know if your computer is infected with a virus

Now that you have eliminated all viruses from your computer, let’s see how you can detect any new viruses in the future. Become an expert in malware detection and learn how to spot a virus infection by paying attention to the following symptoms:

• Your system is running slower than usual. A virus may be using your computer’s resources to replicate itself. Since it has less computing power to perform its operations, your computer slows down and its performance degrades.

• Ads and pop-ups appear on your desktop. Many viruses fall into the category of adware: malware created to flood you with advertisements to generate revenue for the cybercriminal. A sudden onslaught of advertisements could very well be the work of a virus.

• You find programs or software that you did not install on your computer. Viruses can download other malware to your computer to commit other cyber crimes. The only programs on your computer should be those you installed yourself or those installed by the manufacturer.

• Your system starts behaving strangely. If a virus reaches the vital organs of your computer, you may notice certain undesirable effects such as crashes, stoppages or blocking of applications.

• Your Internet connection suddenly slows down, or your bandwidth explodes. Malware that sends bulk data, such as botnets or spyware, affect your internet speed.

• Your antivirus is reporting an infection. If you are using a legitimate antivirus software, trust it! It will take care of removing this threat or other malware for you.

It is important to note that these problems can also be caused by something other than viruses, for example an overloaded downloads folder or a full cache. Computers can become cluttered faster than you think, and this buildup can have the consequences described above. Use a cleanup tool like Avast Cleanup to get rid of clutter and get your PC back to full performance.

If you are sure your computer is infected, but your anti-malware software has not detected or removed any viruses, what can you do? All you have to do is go back a little higher in this article and read again how to eliminate a virus!

Can my other devices be infected?

Windows PCs aren’t the only devices susceptible to virus attacks. Today, virtually any device can be infected with malware, including Macs and phones. That’s why it’s important to scan your devices for malware, no matter what type of device you’re using.

Virus removal methods depend on what you are using. removing a virus on a Mac is very different from removing a virus on Android or < span rel="noopener">malware on iOS. No matter what device you use, your best defense against viruses is reliable antivirus from a reputable vendor.

I thought Windows Defender protected me from viruses?

Windows Defender provides protection against viruses, but is not as effective against other types of threats.

This recent benchmarking shows that Windows Defender is doing quite well, but not as well as other antiviruses. Microsoft’s tool certainly defends you against most malware, but Windows Defender is no match for data theft, intrusions on Wi-Fi networks and other cyber threats.

That’s why we recommend that you protect your devices with comprehensive and specialized cybersecurity software.

Easily remove viruses and malware

One of the main advantages of cybersecurity tools is their ability to detect and remove viruses and other malware from your device in real time. Avast One runs in the background, finds traces of viruses or other malware, and removes them before they can infect your machine. And our software is constantly updated to respond to new threats as they are discovered, to provide you with continuous protection in an ever-changing web environment.

By choosing Avast One, you join the hundreds of millions of users worldwide who trust Avast for their PC security.