Dual Anti-Virus: Is it Worth It?

TL;DR

Running two anti-virus programs can improve cyber security, but it’s often more trouble than it’s worth. Conflicts can slow down your computer and even make it less secure. Focus on a good single solution with strong real-time protection and regular updates.

Understanding the Risks & Benefits

The idea behind using two anti-virus programs is to have multiple layers of defence. If one misses something, the other might catch it. However, modern anti-virus software is already very effective, and adding another can cause problems.

Why Two Anti-Virus Programs Can Cause Issues

• Performance Impact: Both programs scan files simultaneously, using up significant CPU and memory resources. This slows down your computer, especially during tasks like opening files or browsing the web.
• Conflicts & Instability: They can interfere with each other, leading to crashes, errors, and even preventing one or both from working correctly.
• False Positives: Two scanners are more likely to flag legitimate software as malicious (false positives), causing unnecessary alerts and potential disruption.
• Reduced Effectiveness: Some anti-virus programs actively block other security software. This can disable real-time protection or prevent updates, leaving you vulnerable.

Steps to Check for Conflicts

1. Check Compatibility Lists: Before installing a second program, see if your existing anti-virus vendor has a list of compatible software on their website. For example, Bitdefender publishes compatibility information here (example link).
2. Disable Real-Time Protection Temporarily: After installing the second program, temporarily disable real-time protection in one of them to see if it causes conflicts.
3. Event Viewer Checks: Look for errors related to anti-virus software in Windows Event Viewer.
   • Press Win + R, type eventvwr.msc and press Enter.
   • Navigate to Windows Logs > Application.
   • Filter for events with sources related to your anti-virus programs (e.g., ‘Kaspersky’, ‘Norton’, ‘Bitdefender’). Look for errors or warnings.

Better Alternatives to Dual Anti-Virus

1. Choose a Strong Single Solution: Invest in a reputable anti-virus program with consistently high ratings from independent testing labs like AV-Test (https://www.av-test.org/) and SE Labs (https://selabs.uk/).
2. Enable a Firewall: Windows Firewall is sufficient for most users, but consider a third-party firewall if you need more advanced features.
3. Keep Software Updated: Regularly update your operating system and all applications to patch security vulnerabilities.
   • Windows Update: Go to Settings > Update & Security > Windows Update and check for updates.
   • Third-Party Apps: Use the built-in updater in each application, or consider a software update tool like Patch My PC (https://patchmypc.com/).
4. Use Anti-Malware Software: Consider running a separate anti-malware scanner (like Malwarebytes) occasionally for a second opinion, but don’t run it constantly alongside your main anti-virus.

   malwarebytes --scan

5. Practice Safe Browsing: Be cautious about clicking links in emails or downloading files from untrusted sources.