How to Run an Antivirus Scan

Everyone · How-to · Updated October 1, 2026 · LearnLife Editorial

What do you need before starting an antivirus scan?

Before starting an antivirus scan, you need a few essentials to ensure the process goes smoothly and effectively. First, confirm that your device has antivirus software installed—this could be a built-in program like Windows Defender or a third-party application. If you don’t have antivirus software yet, select a trusted program and install it according to the developer’s instructions.

Next, make sure the antivirus software is fully updated. Updates include new virus definitions, which help the program detect the latest threats. To update, open your antivirus software and look for an "Update" or "Check for updates" button. It’s best to connect your device to the internet during this step so it can download necessary updates.

Before scanning, close unnecessary applications to free up system resources. Running heavy programs during the scan can slow down the process or cause it to fail. Additionally, save any important work since some scans might require a restart or temporarily affect device performance.

For example, if you plan to scan a laptop, plug it into power to avoid interruption due to low battery. Finally, ensure your device is not in “sleep” or “hibernate” mode during the scan, as this can pause or stop the process.

How do you run an antivirus scan step-by-step?

Running an antivirus scan involves several straightforward steps designed to identify and remove malware:

1. Open the antivirus software: Find the program icon in your system tray, desktop, or start menu and double-click it to open the main window.
2. Update virus definitions: Before scanning, check for updates within the app. This ensures your antivirus recognizes the newest threats.
3. Select the scan type: Most programs offer at least two options: Quick scan: Checks common malware hiding places such as system files, running processes, and startup items. It’s faster but less thorough. Full scan: Inspects every file and program on your device, including external drives if selected. It takes longer but is more comprehensive.
4. Start the scan: Click the button labeled “Scan,” “Start Scan,” or similar. The program will begin analyzing files and memory.
5. Wait for the scan to finish: Depending on your device and scan type, this can take from a few minutes to several hours. Avoid interrupting it.
6. Review the results: When done, the antivirus will display a report showing if any threats were found. This report often includes file names, threat categories, and suggested actions.
7. Take recommended actions: Follow prompts to quarantine, delete, or ignore detected threats. Quarantining isolates suspicious files without deleting them, allowing you to restore files if needed.

For example, if the scan finds a suspicious file named “example.exe,” the software might recommend quarantining it first to observe if it affects your device before permanent removal.

How can you tell if the antivirus scan worked?

Knowing whether your antivirus scan worked depends on clear indicators and actions after completion. First, a successful scan completes without error messages or interruptions. If the software closes unexpectedly or displays errors, the scan may not have run properly.

Once finished, the antivirus program should provide a detailed report. This report usually lists the total number of files scanned, the scan duration, and any threats found. If no threats are detected, you’ll see a message such as “No threats found” or “Your device is clean.” If threats are detected, the program will suggest actions like quarantine or removal.

You can also check the antivirus program’s status dashboard or icon on your device. A green checkmark or “Protected” status typically means the software is working well and your device is secure.

To further verify, consider testing your antivirus with safe, simulated malware files called EICAR test files. These files mimic virus signatures without causing harm and can confirm your antivirus responds correctly.

Finally, monitor your device’s performance. After the scan and removal of threats, it should run smoother without unexpected crashes, pop-ups, or slowdowns.

What should you do when an antivirus scan goes wrong?

If your antivirus scan encounters problems, such as failing to start, freezing, or producing error messages, follow these troubleshooting steps:

• Restart your device: Sometimes, simply rebooting resolves temporary glitches.
• Update the antivirus software: An outdated program may malfunction. Open the app and run the update process again.
• Close other applications: Background programs might interfere with scanning. Close all non-essential apps before retrying.
• Run the scan in safe mode: Safe mode starts your device with minimal software running—a good environment for scanning. To enter safe mode, restart your device and press the appropriate key during startup (this varies by device and operating system).
• Check for software conflicts: Having multiple antivirus programs can cause scans to fail. Uninstall any other antivirus software to avoid conflicts.
• Reinstall the antivirus program: If problems persist, uninstall and reinstall the antivirus software following official instructions.
• Seek professional help: If malware is preventing scans or causing serious issues, contact a trusted technician or the antivirus software’s customer support.

If the scan finds malware but cannot remove it, consider backing up important data and running additional malware removal tools or contacting a computer security professional.

How do you adapt antivirus scanning for different devices?

Different devices have unique operating systems and antivirus solutions, requiring slightly different scanning methods:

• Windows and Mac computers: Run scans via installed antivirus apps. For Windows, programs like Windows Defender or third-party software offer quick and full scans. On a Mac, antivirus apps scan the system and external drives. Scheduling scans overnight can help avoid downtime.
• Laptops: Similar to desktop computers, but keep the device plugged in during scans to prevent interruption from battery loss. On laptops, scans may take longer if you have multiple external drives connected.
• Android devices: Use antivirus apps designed specifically for Android. Open the app, tap “Scan” or similar, and allow it to check apps, downloads, and storage. Since Android allows app installation from outside the Play Store, scanning regularly can catch risky apps or infected files (How to Run an Antivirus Scan on Android Devices).
• iPhones: iOS has built-in security features restricting direct antivirus scans. Instead, keep your device updated and avoid suspicious downloads. Use security apps focused on privacy and phishing protection (How to Run an Antivirus Scan on an iPhone).
• Other devices: Tablets, smart TVs, and other smart devices may have limited antivirus options. Regular software updates and cautious usage habits are key.

For example, if you use your phone to download many apps, running scans weekly with an Android antivirus app can reduce risks. For a laptop used for work, schedule full scans monthly and quick scans weekly.

What are tips for maintaining antivirus protection after a scan?

Antivirus scans are a vital defense, but ongoing protection requires consistent habits:

• Keep antivirus software updated: Enable automatic updates if available.
• Schedule regular scans: Set quick scans weekly and full scans monthly through your antivirus settings.
• Practice safe browsing: Avoid clicking on suspicious links or downloading attachments from unknown sources.
• Use strong passwords and two-factor authentication: Protect accounts that could be targeted by malware.
• Backup important files regularly: In case malware damages or encrypts your data, backups ensure recovery.
• Combine antivirus with other security tools: Firewalls, password managers, and ad blockers add layers of protection.
• Monitor scan reports: Review past scan results to spot repeated threats or unusual files.
• Educate yourself about new threats: Stay aware of common scams and malware types by consulting trusted sources (How to Increase Online Privacy Effectively).

For example, if you frequently shop online or handle sensitive information, running scans after downloading files or visiting new websites helps catch threats early.

Following these practices keeps your device safer and ensures that antivirus software remains effective over time.

Frequently asked questions

Can I scan a USB drive with antivirus software?

Yes, most antivirus programs allow you to scan external drives like USB sticks. Connect the USB drive, open your antivirus software, select the option to scan external or removable media, and start the scan to check for viruses.

What should I do if my antivirus finds a false positive?

Sometimes antivirus programs mistakenly flag safe files as threats. If you believe this happened, check the file’s source and scan it with another trusted antivirus tool. You can also report the false positive to the software’s support team to improve accuracy.

Is a full scan necessary every time I run an antivirus check?

Full scans are thorough and recommended periodically (e.g., monthly) but can take a long time. Quick scans are sufficient for routine checks and can be run more frequently to catch common threats faster.

How do I know which antivirus software to choose?

Look for antivirus programs with good reputations, regular updates, and features that fit your needs (like malware removal, phishing protection, or system optimization). Reading user reviews and consulting trusted sources can help you decide.

Can antivirus software protect me from phishing emails?

Antivirus programs may detect some phishing links, but they cannot catch all. It’s essential to be cautious with emails asking for personal information and to use email filters and security features alongside antivirus software.

What happens if I ignore antivirus scan results?

Ignoring scan results can leave malware on your device, risking data loss, identity theft, or system damage. Always review and act on the scan’s recommendations to keep your device safe.