A computer virus can cause slow performance, unwanted pop-ups, unexpected crashes, browser redirects, or other unusual behavior. In more serious cases, malware can damage files, steal information, or interfere with normal system operations.

If you suspect your computer has a virus, don’t panic. Many infections can be detected and removed using reputable security tools and careful troubleshooting.

This guide explains how to remove computer viruses safely from Windows and Mac computers.

What Is a Computer Virus?

A computer virus is a type of malicious software that can replicate or spread by attaching itself to files or programs. The broader term malware includes viruses as well as other threats such as trojans, spyware, ransomware, and worms.

Common signs of a possible malware infection include:

• Unexpected pop-ups
• Slow computer performance
• Frequent crashes
• Unknown applications
• Browser redirects
• Unusual system behavior
• Disabled security software
• Unknown files appearing on the device
• Unexplained network activity

One symptom alone does not necessarily mean your computer is infected. Hardware problems, unwanted applications, or browser extensions can cause similar behavior.

Step 1: Disconnect From the Internet

If you strongly suspect an active malware infection, disconnect the computer from the internet temporarily.

You can:

• Turn off Wi-Fi.
• Disconnect the Ethernet cable.
• Disable network connections through your system settings.

This can help limit communication between malware and external servers while you investigate the problem.

For ordinary browser pop-ups or suspected unwanted software, you may not need to disconnect immediately.

Step 2: Don’t Enter Sensitive Information

If you suspect malware, avoid entering:

• Banking passwords
• Email passwords
• Credit card information
• Authentication codes
• Other sensitive credentials

If you later determine that credentials may have been exposed, change them from a known-clean device.

Step 3: Update Your Security Software

Use a reputable antivirus or built-in security solution and make sure it is fully updated.

Security updates can improve the software’s ability to recognize newer threats.

On Windows, you can use Windows Security to check your device’s protection status.

On Mac, keep macOS and your security software updated.

Step 4: Run a Full Malware Scan

Start with a full or thorough system scan rather than relying only on a quick scan.

Depending on the amount of data stored on your computer, the scan may take some time.

If the security software detects a threat, follow its recommended removal or quarantine instructions.

Don’t manually delete system files unless you know exactly what they are.

Step 5: Quarantine or Remove Detected Threats

Security software may give you options such as:

• Quarantine
• Remove
• Delete
• Repair

Quarantine is often useful because it isolates a suspicious file so it cannot run normally while allowing the security software to manage it safely.

Follow the recommendations provided by your security software.

Step 6: Restart the Computer

After removing detected malware, restart your computer if the security software recommends it.

Some security tools may require a restart to complete the removal process.

After restarting, run another scan if necessary.

Step 7: Remove Suspicious Applications

Review the applications installed on your computer.

Look for programs you don’t recognize or software that appeared around the time the problems started.

On Windows, you can review installed applications through Settings > Apps.

On Mac, review the Applications folder.

Before uninstalling anything, verify that it isn’t a legitimate system component or application.

Step 8: Check Your Browser

Malicious or unwanted browser extensions can cause:

• Redirects
• Pop-ups
• Changed search engines
• Unknown homepages
• Suspicious advertisements

Review your browser extensions and remove extensions you don’t recognize or no longer need.

Also check the browser’s:

• Homepage
• Default search engine
• Notification permissions
• Site permissions

Resetting browser settings may help if unwanted changes continue.

Step 9: Install Operating System Updates

After dealing with the suspected infection, install available security updates.

Windows

Open Settings > Windows Update and check for available updates.

Mac

Open System Settings > General > Software Update and install available updates.

Keeping the operating system current can help protect against vulnerabilities that attackers may exploit.

Step 10: Check Your Online Accounts

If you believe malware may have captured passwords or other sensitive information, secure your important accounts.

From a known-clean device:

1. Change compromised passwords.
2. Use unique passwords for each account.
3. Enable multi-factor authentication.
4. Review recent login activity.
5. Sign out unfamiliar sessions.
6. Check for unauthorized account changes.

Start with your primary email account because it may be used to reset other passwords.

How to Remove a Virus From Windows

Windows includes built-in security tools that can scan for malware.

Basic process:

1. Open Windows Security.
2. Select Virus & threat protection.
3. Check for security updates.
4. Run a scan.
5. For a suspected infection, use the most thorough available scan option.
6. Follow the recommended actions for detected threats.
7. Restart the computer if required.
8. Run another scan if necessary.

For persistent infections, Microsoft provides additional recovery and offline scanning options through Windows Security.

How to Remove Malware From Mac

Mac computers include built-in security technologies designed to help prevent and detect malicious software.

If you suspect malware:

1. Update macOS.
2. Review recently installed applications.
3. Remove suspicious applications.
4. Review browser extensions.
5. Check browser settings.
6. Run a reputable security scan if needed.
7. Restart the Mac.
8. Monitor the system for recurring symptoms.

Avoid downloading random “Mac cleaner” or “virus removal” programs from pop-ups. Some fake security applications are themselves unwanted or malicious.

What If the Virus Keeps Coming Back?

If the same threat repeatedly returns, don’t continue deleting files randomly.

Possible causes include:

• The original malware wasn’t completely removed.
• A malicious application is reinstalling it.
• A browser extension is responsible.
• Another device or account is compromised.
• System files have been affected.

At this point, use a reputable security tool’s recommended recovery process or seek qualified technical assistance.

When Should You Reset or Reinstall the Computer?

A complete reset or operating system reinstall may sometimes be appropriate for a severe or persistent infection, particularly when you cannot confidently establish that the system is clean.

Before doing this:

• Back up important personal files carefully.
• Make sure the backup isn’t infected.
• Confirm you have access to important account credentials.
• Make sure you have necessary software licenses.
• Keep recovery information available.

Don’t restore suspicious executable files or applications from an untrusted backup.

How to Prevent Future Virus Infections

After removing malware, improve your security habits.

Keep Everything Updated

Install updates for your operating system, browsers, applications, and security software.

Download Software Carefully

Use official websites and reputable app stores.

Avoid pirated or modified applications.

Be Careful With Email

Don’t open unexpected attachments or click suspicious links.

Use Strong Passwords

Use unique passwords and enable multi-factor authentication on important accounts.

Maintain Backups

Regularly back up important files and keep at least one backup separated from the main computer.

Use Security Software

Keep your antivirus or built-in security protection enabled and updated.

Common Mistakes When Removing Viruses

Avoid these mistakes:

• Downloading random “virus removal” software from pop-ups
• Disabling antivirus protection unnecessarily
• Deleting system files manually
• Continuing to use compromised accounts
• Ignoring security updates
• Restoring suspicious files from backups
• Assuming a slow computer automatically means a virus

Frequently Asked Questions

Can I remove a computer virus myself?

Many common malware infections can be handled using reputable security software and built-in operating system tools. More serious or persistent infections may require professional assistance.

Should I delete the infected file manually?

Not necessarily. Let your security software identify and quarantine or remove the threat when possible. Manually deleting system files can cause additional problems.

Will resetting my computer remove a virus?

A properly performed operating system reset can remove many forms of malware, but you should carefully protect your personal data and avoid restoring infected applications or files.

Can antivirus remove every virus?

No security tool can guarantee detection of every threat. Malware constantly evolves, which is why updates, backups, and safe online behavior remain important.

Final Thoughts

Learning how to remove computer viruses starts with staying calm and avoiding unnecessary actions. Disconnect the device when appropriate, update your security software, perform a thorough scan, quarantine detected threats, and review suspicious applications and browser extensions.

If sensitive credentials may have been exposed, secure your accounts from a known-clean device. For severe or persistent infections, consider professional technical assistance or a complete system recovery.

The best defense is prevention: keep your software updated, use reputable security protection, avoid suspicious downloads and links, and maintain reliable backups.