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Does Your Computer Have a Virus? Here’s How to Tell

Have you noticed your computer slowing down or acting strangely recently? If so, you may have a virus. Computer viruses are far more widespread than most people realize – in 2022 alone, ransomware infected 37% of organizations globally. But don‘t panic yet. While viruses can certainly cause hassles, they are treatable conditions if caught early. This comprehensive guide will walk you through how to definitively diagnose a virus, remove it for good, and implement bulletproof precautions that keep your computer safe well into the future.

How to Know if Your Computer Has a Virus

Viruses produce an array of unusual symptoms that can clue you in to a potential infection. If you notice any of the following, it‘s very likely your computer has been compromised:

  • Extremely sluggish performance – Tasks like opening apps, browsing websites, or booting up will take much longer than normal. Viruses overwhelm your CPU and memory with useless processes, significantly slowing everything down.
  • Frequent crashing or freezing – The virus may force constant computer restarts, crashes, freezes, or the infamous Blue Screen of Death.
  • Weird pop-up ads – Aggressive pop-up ads are a preferred distribution method for viruses. If you suddenly see multiple pop-ups, especially for sketchy products, it points to an infection.
  • Unfamiliar programs – Check your apps and downloads for anything you don‘t recall installing yourself. Viruses often disguise malicious software as useful utilities or plugins.
  • Browser redirects – Viruses modify browser settings to send traffic to phishing sites or spam downloads for financial gain. Watch for unexpected homepage or search engine changes.
  • Unsent emails from your account – Viruses will stealthily send infected emails to contacts to spread themselves. Watch for confused responses about emails you never sent.
  • Disabled antivirus – Sneakier viruses will attempt to turn off your antivirus to avoid elimination. Verify your antivirus is still active and updating.
  • Inaccessible files/device – Ransomware encrypts your data until you pay a ransom. You‘ll quickly lose access to critical files or potentially your whole system.

If any of these red flags pop up, there‘s a high probability your computer has been infected. But stay calm – removing viruses is a very manageable process.

How to Remove an Existing Virus

Once a virus is detected, promptly follow these removal best practices to eliminate it before greater harm occurs:

Run In-Depth Antivirus Scans

Your first response should be to perform full system scans using your antivirus software. Quick scans only check selective spots and can miss viruses, while full scans dig deeper into every nook and cranny for malware.

I recommend an advanced antivirus like McAfee or Bitdefender for maximum detection rates. Also, update your antivirus fully before scanning to catch latest viruses.

If infections are found, let your antivirus software delete or quarantine them. But don‘t assume one scan means you‘re done – tenacious viruses occasionally slip by. Run additional periodic scans over the next week to catch any stragglers.

Update and Patch All Software

Double check that your operating system, web browsers, plugins, drivers and other installed software are completely updated. Cyber criminals exploit security flaws in outdated programs to inject their viruses.

Only download updates from official developer channels like the Microsoft Store or Google Play to avoid malware-laden fakes from third parties.

Reset Browser Settings

Viruses love to modify browser settings for evil purposes like redirecting your web traffic to phishing pages. After removing an infection, reset your browser to factory default settings to undo any unwanted changes.

You can then reconfigure your custom options like bookmarks once the reset is finished. This gives you a blank slate to ensure no virus alterations remain.

Delete Virus Files

Scrutinize your computer for any leftover files identified as infected by antivirus scans. This includes downloads, browser caches, temp folders, external drives and any suspicious locations.

Be thorough – viruses use sneaky tricks like renaming themselves as legitimate system files or using double extensions. When in doubt, delete. Don‘t just quarantine, as infected files still take up drive space and can potentially re-spread if activated.

Disconnect From Networks

Temporarily unplug Ethernet cables and turn off WiFi to isolate your computer. This prevents the virus communicating across your network and infecting other connected devices like smartphones or tablets.

For extra protection, you can also unplug external storage media that may have transferred the virus initially.

Scan Connected Devices

After removing the virus and disconnecting networks, reconnect your computer and scan any linked devices like external hard drives. This verifies the virus is fully eradicated across all endpoints.

Yes, it‘s a monotonous process. But viruses are notoriously stubborn and can easily spread across multiple devices if left unchecked. Better safe than sorry.

Try System Restore

Windows users should attempt a System Restore to roll your computer back to an earlier point before the virus infection occurred. This can directly undo any system changes made by the virus.

Click Start, type "System Restore" and choose a restore point from before you noticed any virus symptoms. This won‘t remove existing infected files but can fix registry changes.

Reset System Files

As a final cleanup step for Windows users, run the System File Checker tool. This scans for corrupted system files modified by viruses and replaces them with original clean copies.

To run, open the Command Prompt as Administrator and enter “SFC /scannow”. Let the full scan proceed to completion – this can take a while.

If these removal tactics still don‘t wipe out a lingering virus, don‘t hesitate to take your computer into a repair technician. Their advanced diagnostics tools and virus removal experience can fully eliminate even the most stubborn infections.

How to Prevent Viruses in the Future

Eliminating an existing virus is crucial. But just as important is bulletproofing your computer to prevent brand new infections going forward. Here are my top virus prevention tips:

Install Premium Antivirus Software

Top-tier antivirus programs like Norton 360 or McAfee Total Protection should be your first line of defense. Premium options provide much stronger real-time protection versus low-cost or free antivirus.

Enable automatic updates and scans for uncompromising security. Also consider complementary firewall, VPN and password manager tools.

Update Software Frequently

Consistently update your operating system, browsers, drivers, plugins, utilities and other software whenever patches are released. Hackers continually probe programs for new vulnerabilities to infiltrate.

Only download updates directly from trusted developers like Microsoft or Adobe to avoid malware bundled into fakes.

Avoid Suspicious Links and Emails

Exercise caution when opening emails, messaging attachments, and clicking links, especially from unrecognized senders. Viruses thrive when disguised inside malicious links and documents.

Even messages that appear to come from friends can harbor infected attachments if their accounts were compromised. When in doubt, verify legitimacy before clicking or downloading anything.

Only Install Trusted Software

Only download programs and applications from official trusted sources like the Microsoft Store or Steam. Avoid torrent sites, "cracked" software, and other questionable outlets teeming with malware bundles.

Even trusted sites can unknowingly host infected software on occasion, so stay vigilant. Rely on reviews to spotlight any red flags with a download before installing.

Make Regular Backups

Back up your computer to an external hard drive or cloud storage on a regular basis. This gives you a clean restore point if ransomware encrypts your system.

I recommend the 3-2-1 backup strategy – three copies, on two different media types, with one offsite. This protects you from both data corruption and physical disasters.

Use Strong Passwords

Weak passwords make it simple for viruses to spread across all your online accounts. Use long, complex passwords that are unique for every account.

Enable two-factor authentication anywhere available for extra security. Password managers like Dashlane also generate and store strong passwords safely.

Don‘t Use Public Computers

Avoid using internet cafes, library computers, and other public devices when possible. These commonly have poor security and are hotbeds for infections that are easily picked up.

Watch for Phishing Scams

Keep your guard up for phishing emails, texts, calls and other scams aiming to steal your information through social engineering. These can be used to distribute viruses or gain backdoor access into systems.

Be especially cautious entering any sensitive data into websites – only use sites you initiated access to yourself with known legitimate URLs.

Install a Firewall

Make sure your operating system firewall is enabled for basic inbound connection filtering. Even better, install a dedicated third party firewall for much stronger outgoing and inbound traffic blocking.

Firewalls create crucial barriers that prevent malicious traffic from either entering or exiting your computer.

The combination of safe browsing habits, top-tier security software, vigilant updates, backups, and firewalls will help you avoid the headaches of virus infections altogether. But if one still squeaks through, apply the removal best practices outlined here to get your computer‘s health back on track quickly. Staying virus-free may require some diligence, but is well worth it for your computer‘s stability and safety in the long run.


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