how to fix "turn on virus protection" pop up

Remove the suspicious website from Chrome’s notification permissions first, then check Windows Security separately to determine whether antivirus protection is actually off.

Stop the Chrome alerts

1. Open Chrome.
2. Select ⋮ (three dots) → Settings.
3. Select Privacy and security → Site settings → Notifications.
4. Under Allowed to send notifications, locate any website you do not recognize.
5. Select the three dots beside it, then choose Remove or Block.
6. To prevent future requests, change the default notification setting so sites cannot ask to send notifications. ^1^

Also open Chrome → Settings → Extensions and remove unfamiliar extensions. If alerts, unwanted tabs, or redirects continue, Chrome’s cleanup guidance recommends removing unwanted extensions and resetting altered browser settings. ^2^

Do not click the alert, call a displayed number, install anything it recommends, or provide payment or personal information. Fake security messages commonly come from malicious or compromised websites, and genuine Microsoft warnings do not include telephone numbers. ^3^

If a pop-up takes over the browser, press Alt+F4 to close it. If that fails, restart the computer. ^4^

Confirm whether antivirus is genuinely disabled

Do not use the Chrome message to judge Defender’s status:

1. Open Start and search for Windows Security.
2. Open Virus & threat protection.
3. Check its status. A green status indicates sufficient protection; yellow indicates a recommendation, and red requires attention. ^5^
4. If Windows Security reports that real-time protection is off, select Virus & threat protection → Manage settings, then turn Real-time protection on. ^6^
5. Return to Virus & threat protection and run Quick scan.

If another antivirus product is installed and active, Microsoft Defender Antivirus may be disabled in favor of that product. If no other working antivirus exists, Defender can be enabled manually and normally turns on automatically. ^7^

If Windows Security is green and its scan finds nothing, but the Chrome notices stop after removing the website permission, they were browser notification spam rather than a genuine Windows antivirus warning.

References

1. Use notifications to get alerts - Computer - Google Chrome Help
2. Remove unwanted ads, pop-ups & malware - Computer - Google Chrome Help
3. Protect yourself from tech support scams | Microsoft Support
4. Protect yourself from online scams and attacks | Microsoft Support
5. Windows Security App Overview | Microsoft Support
6. Stay protected with the Windows Security app | Microsoft Support
7. Antivirus and antimalware software: FAQ | Microsoft Support