Outdated security software on Windows 11 PC

For most Windows 11 users, Microsoft Defender Antivirus is sufficient and there is usually no need to install a third-party antivirus.

Defender is built into Windows, receives security intelligence updates through Windows Update, and includes real-time protection, firewall integration, ransomware protection, and cloud-based threat detection. It also tends to cause fewer compatibility issues than older third-party security software.

I would first uninstall the outdated antivirus, preferably using the vendor’s official removal tool, then restart the PC. Windows Security should automatically reactivate Microsoft Defender.

After that, check:

Windows Security > Virus & threat protection

Make sure real-time protection is enabled and run a definition update followed by a full scan. Also install any pending updates under Settings > Windows Update.

Avoid running two antivirus programs with real-time protection at the same time, since that can cause conflicts, slowdowns, and update problems.