When your Windows 11 PC displays a “Security Certificate Cannot Be Verified” error, it means your computer cannot confirm the authenticity of a website, application, email server, or network connection. Security certificates, also known as SSL/TLS certificates, are used to encrypt data and verify the identity of the server you’re connecting to. If Windows cannot validate the certificate, it blocks the connection to help protect you from potential security threats.
This error can appear in web browsers, Microsoft Outlook, Microsoft Office, Windows Update, VPN software, Remote Desktop, or other applications that rely on secure connections. In many cases, the problem isn’t with the certificate itself—it may be caused by an incorrect system date and time, outdated root certificates, network issues, browser cache, antivirus software, or Windows configuration problems.
Fortunately, you can usually resolve the issue using built-in Windows tools without installing any third-party software. In this guide, we’ll explain why the error occurs and walk you through the best methods to fix the Security Certificate Cannot Be Verified error in Windows 11.
What Causes the Security Certificate Cannot Be Verified Error?
Several factors can prevent Windows from validating a security certificate, including:
- Incorrect system date or time.
- Expired or invalid SSL/TLS certificate.
- Outdated Windows root certificates.
- Browser cache or corrupted SSL cache.
- Antivirus software inspecting HTTPS traffic.
- Proxy or VPN configuration issues.
- Corrupted Windows system files.
- Network connectivity problems.
- Incorrect DNS settings.
- Firewall restrictions.
Identifying the cause helps you apply the appropriate solution.
Method 1: Check the Date and Time Settings
An incorrect system clock is one of the most common causes of certificate verification failures.
- Press Windows + I to open Settings.
- Select Time & language.
- Click Date & time.
- Turn on Set time automatically.
- Turn on Set time zone automatically if available.
- Click Sync now.
- Restart your computer.
Try accessing the website or application again after the restart.
Method 2: Verify the Certificate Has Not Expired
If the error appears only on a specific website, the certificate itself may have expired.
To check:
- Open the website in your browser.
- Click the padlock icon next to the address bar.
- View the certificate information.
- Check the expiration date.
- Verify that the certificate was issued by a trusted certificate authority.
If the certificate has expired, only the website owner can resolve the issue.
Method 3: Update Windows
Windows updates include newer trusted root certificates and security improvements.
To install updates:
- Open Settings.
- Go to Windows Update.
- Click Check for updates.
- Install all available updates.
- Restart your computer.
After updating, test the secure connection again.
Method 4: Clear the SSL State
Windows stores SSL certificate information in a local cache. Clearing this cache can resolve certificate-related issues.
- Press Windows + S.
- Search for Internet Options.
- Open Internet Options.
- Select the Content tab.
- Click Clear SSL state.
- Wait for the confirmation message.
- Click OK.
- Restart your browser.
Windows will rebuild the SSL cache automatically.
Method 5: Enable TLS 1.2
Many modern websites require TLS 1.2 or newer.
- Open Internet Options.
- Go to the Advanced tab.
- Scroll to the Security section.
- Check Use TLS 1.2.
- If available, also enable Use TLS 1.3.
- Click Apply.
- Click OK.
- Restart your PC.
This ensures Windows can establish secure encrypted connections using supported protocols.
Method 6: Clear Browser Cache
Corrupted browser data may trigger certificate errors.
For most browsers:
- Open browser settings.
- Navigate to Privacy or History.
- Choose Clear browsing data.
- Select cached images and files.
- Optionally clear cookies if appropriate.
- Restart the browser.
Then revisit the affected website.
Method 7: Disable HTTPS Scanning in Antivirus Software
Some antivirus programs inspect encrypted traffic, which can interfere with certificate validation.
Temporarily disable features such as:
- HTTPS scanning.
- SSL scanning.
- Encrypted connection scanning.
- Web protection.
After disabling the feature, test the connection. If the error disappears, re-enable protection and check for antivirus updates or configuration options.
Method 8: Flush the DNS Cache
A stale DNS cache can occasionally cause secure connection issues.
- Open Command Prompt as Administrator.
- Run:
ipconfig /flushdns- Wait for the confirmation message.
- Restart your browser.
This forces Windows to obtain fresh DNS information.
Method 9: Reset Network Settings
Corrupted network settings may prevent certificate validation.
- Open Settings.
- Go to Network & Internet.
- Select Advanced network settings.
- Click Network reset.
- Choose Reset now.
- Restart your computer.
You’ll need to reconnect to your Wi-Fi network afterward.
Method 10: Run System File Checker
Damaged system files can affect Windows security services.
- Open Command Prompt as Administrator.
- Run:
sfc /scannow- Wait for the scan to complete.
- Restart your PC.
If issues remain, run:
DISM /Online /Cleanup-Image /RestoreHealthRestart once the process finishes.
Method 11: Disable Proxy or VPN Temporarily
A proxy server or VPN may present certificates that Windows cannot verify.
To test:
- Open Settings.
- Go to Network & Internet.
- Select Proxy.
- Disable any proxy settings if they’re not required.
- Disconnect any active VPN.
- Test the connection again.
If the error disappears, review the proxy or VPN configuration before reconnecting.
Method 12: Try a Different Network
If the error occurs only on one network, the issue may be caused by:
- Public Wi-Fi login pages.
- School or office firewalls.
- ISP DNS issues.
- Router security settings.
Connect to another Wi-Fi network or use a mobile hotspot to see if the problem persists.
Common Certificate Error Messages
You may encounter variations of this error, such as:
- Security Certificate Cannot Be Verified
- This site’s security certificate isn’t trusted
- SSL Certificate Error
- Your connection is not private
- Certificate chain was issued by an untrusted authority
- NET::ERR_CERT_AUTHORITY_INVALID
- Certificate has expired
Although the wording differs, the troubleshooting steps are often similar.
Is It Safe to Ignore Certificate Errors?
Generally, no.
Ignoring certificate warnings can expose you to:
- Phishing websites.
- Data interception.
- Identity theft.
- Malware distribution.
- Man-in-the-middle attacks.
Only proceed if you fully trust the website or server and understand why the certificate warning appears, such as when using a self-signed certificate in a controlled environment.
Tips to Prevent Certificate Errors
To reduce the chances of certificate-related issues:
- Keep Windows updated.
- Enable automatic date and time synchronization.
- Use a modern, updated web browser.
- Keep antivirus software up to date.
- Avoid connecting through untrusted public Wi-Fi without protection.
- Regularly clear browser cache if you experience browsing issues.
- Ensure TLS 1.2 or newer is enabled.
- Restart your PC after installing major updates.
These practices help maintain secure and reliable connections.
Frequently Asked Questions
Why does this error appear on only one website?
The website may have an expired, misconfigured, or untrusted certificate. Alternatively, your browser may have cached outdated certificate information.
Does clearing the SSL state delete passwords?
No. Clearing the SSL state only removes cached SSL certificate data. It does not delete saved passwords, bookmarks, or browsing history.
Can an antivirus program cause certificate errors?
Yes. Some antivirus programs inspect encrypted HTTPS traffic and can interfere with certificate validation if their own certificates are outdated or improperly configured.
Will updating Windows fix certificate errors?
In many cases, yes. Windows updates include newer trusted root certificates and security improvements that can resolve certificate verification issues.
Conclusion
The Security Certificate Cannot Be Verified error is a protective security feature that helps prevent your computer from connecting to websites or services with invalid or untrusted certificates. While the message can be frustrating, it often has a straightforward solution, such as correcting the system date and time, clearing the SSL cache, enabling TLS 1.2, updating Windows, or repairing network and system settings.
By following the methods in this guide, you can resolve most certificate verification problems safely and restore secure connections without compromising your system’s security. If the issue is limited to a specific website with an expired or invalid certificate, however, the problem must be fixed by the website owner before the warning will disappear.
