Is your computer suddenly slow, crashing, or plagued by pop-ups? These are classic signs of a virus. This guide provides everything you need to know about how to scan computer for viruses, helping you reclaim your device and protect your data from malicious threats.
Telltale Signs: When You Need to Scan Your Computer for Viruses
Before you run a scan, it helps to know what you’re looking for. While some signs are obvious, other clues can be more subtle.
Obvious Red Flags
If you notice any of these issues, it’s time to run a scan immediately. Common signs of infection include your computer running much slower than usual, frequent application crashes, or a sudden barrage of pop-up ads, even when your browser is closed.
Subtle Clues and Silent Dangers
Not all malware is noisy. Some malicious programs are designed to stay hidden while they capture personal information like credit card numbers.
Watch for subtle clues like your computer’s fan running constantly (a sign of high CPU usage), strange files appearing on your system, or your web browser’s homepage changing without your permission.
Investigating Suspicious Processes in Task Manager
For a quick manual check on Windows, press Ctrl + Shift + Esc to open the Task Manager.
Click “More details,” go to the “Processes” tab, and look for anything with a strange name or unusually high CPU or memory usage.
If you see a suspicious process, right-click it and select “Search online” to quickly find out if it’s a known threat.
How to Scan Computer for Viruses with Built-in Tools
You don’t always need to download third-party software to perform a scan. Modern operating systems have powerful, built-in tools ready to go.
Using Windows Security (Microsoft Defender)
Windows 10 and 11 come with a robust, built-in antivirus tool called Windows Security (or Microsoft Defender). For most users, this is an excellent first line of defense.
- Open Windows Security: Click the Start menu, type “Windows Security“, and select it from the results.
- Navigate to Protection: Click on “Virus & threat protection“.
- Perform a Quick Scan: Click the “Quick scan” button to check the folders where threats are most commonly found.
- Run a Full Scan: For a more thorough check, click “Scan options“, select “Full scan“, and then click “Scan now“. This will check every file and running program on your hard disk.
- Use an Offline Scan for Deep Infections: Some stubborn viruses can interfere with the scanning process. The Microsoft Defender Offline scan runs before Windows fully loads, preventing the malware from activating. You can find this in the “Scan options” menu.
You can refer this guide to activate Windows Security.
Scanning on macOS and Mobile
While Macs are secure, they are not immune to viruses. macOS includes a background tool called XProtect that automatically checks for known malware.
For extra peace of mind, you can use a reputable third-party scanner. On Android, you can trigger a scan via the Google Play Store by tapping your profile icon, selecting “Play Protect” and hitting “Scan“.
Advanced Methods for a Deeper Clean
If you suspect a virus is still present after a basic scan or if you want a second opinion, these advanced methods can help.
- Third-Party Antivirus Software: Reputable programs like Heimdell Security, Malwarebytes, Bitdefender, and Norton offer powerful scanning engines and additional features. A popular strategy is to use Windows Defender for real-time protection and run a manual scan with a tool like Malwarebytes for a second opinion.
- Online Scanners: Websites like VirusTotal allow you to upload a suspicious file and have it analyzed by dozens of different antivirus engines at once. This is great for checking a specific file you’re worried about.
- Bootable Rescue Disks: For severe infections that prevent your computer from starting, a bootable rescue disk is your best bet. You create this on a separate, clean computer and use it to start the infected PC and run a scan outside of the compromised Windows environment.
What to Do After the Scan
Once the scan is complete, you’ll see a list of detected threats.
- Quarantine vs. Delete: Your antivirus will give you options like “Quarantine” or “Delete.” Quarantining isolates the file so it can’t do any harm, which is a safe first step. Deleting removes it permanently.
- Handle False Positives: Occasionally, an antivirus might flag a legitimate program as a threat (a “false positive”). If you are 100% certain a file is safe, you can add it to the exceptions list in your antivirus settings.
- Restart Your Computer: After removing threats, always restart your computer to finalize the cleanup process.
Prevention is Better Than Cure: How to Keep Your PC Virus-Free
The best way to handle a virus is to never get one. Adopt these habits to protect yourself:
- Keep Software Updated: Always install updates for your operating system and applications. These updates often patch security holes that viruses exploit.
- Be Smart About Downloads: Only download software from official websites or trusted repositories. Avoid cracked software and files from peer-to-peer networks.
- Beware of Phishing: Be skeptical of unsolicited emails, especially those with attachments or links. Verify the sender before clicking anything.
- Use a Firewall: Ensure your computer’s firewall is enabled, as it acts as a barrier between your device and the internet.
Frequently Asked Questions (FAQs)
Q1: How often should I scan my computer for viruses?
Your antivirus provides real-time protection, but it’s a good practice to run a quick scan every day and a full scan at least once a week. If you download many files, consider scanning more often.
Q2: Can I use more than one antivirus program at the same time?
You should never have two antivirus programs with real-time protection running simultaneously, as they can conflict and slow down your system. However, using a second, on-demand scanner (like Malwarebytes) alongside a primary real-time protector (like Windows Defender) is a safe and effective strategy.
Q3: What should I do if my computer is too infected to start?
If you can’t log in to Windows, try booting into Safe Mode. This starts Windows with minimal drivers and can prevent the malware from loading, allowing you to run a scan. If that doesn’t work, you’ll need to use a bootable antivirus rescue disk.
Q4: Can Macs and smartphones get viruses too?
Yes. While less common, malware exists for all major platforms, including macOS, Android, and iOS. It’s crucial to follow safe practices on all your devices.
Conclusion
Learning how to scan computer for viruses is a fundamental skill for staying safe in the digital world. By recognizing the signs of an infection, taking preventative measures, and using the right tools, you can protect your valuable data and keep your computer running smoothly. Don’t wait for a problem to strike—make regular scanning and safe habits part of your routine.
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