How to Fix Unable to block this app in Windows 11

Recently Windows Security > Protection History shows the message This application cannot be blocked.Which can be frustrating, but don't worry, here is a complete article that will help you with it, so continue reading:

How to Fix Unable to block this app in Windows 11

1. Leveraging Windows Defender Offline Scanning:

Safe Mode with Networking: To create an environment conducive to malware detection and removal, consider booting your system into Safe Mode with Networking. This mode loads a minimal set of startup programs, potentially allowing Windows Defender to bypass any interference from the malicious application. Consult your device manufacturer's support resources for specific instructions on entering Safe Mode with Networking for your device model.

Windows Security Offline Scan: Once booted into Safe Mode with Networking, launch Windows Security. Navigate to "Virus & threat protection settings" and locate "Scan options." Select the "Windows Security Offline scan" and initiate the scan. This scan operates in an isolated environment, potentially eliminating threats that might be actively impeding standard scans.

2. Mitigating the Malicious Program:

Quarantine or Removal: If you possess a high degree of confidence regarding the application's malicious nature, locate and right-click on the program within either the Start menu or File Explorer. Select "More options" followed by "Uninstall" to remove it from your system. Alternatively, you can navigate to "Protection history" within Windows Security and locate the quarantined application. You can then choose to permanently delete it.

Verification of Source and Legitimacy: If the application's legitimacy is unclear, consult reputable antivirus software vendors' websites to determine if it's flagged as malicious. Conduct online research to investigate the program's purpose and source. If it's a legitimate application you trust, you can create an exclusion within Windows Security to permit its execution.

3. Optional: Submitting the App to Microsoft for Analysis

Microsoft Security Intelligence: In instances where the application's legitimacy remains uncertain and standard antivirus scans are inconclusive, consider submitting the program to Microsoft for analysis. This submission can assist Microsoft in identifying new threats and enhancing future malware detection capabilities. The official Microsoft website provides instructions on submitting suspicious files for analysis.

Additional Considerations:

System Restore (as a last resort): If the aforementioned solutions fail to resolve the issue, consider performing a System Restore to a point in time before the problematic application's installation. System Restore can revert your system files and settings to a known good state.

Seeking Professional Assistance: For complex scenarios, consulting a qualified IT professional is recommended. They possess the expertise to conduct advanced diagnostics and implement effective removal techniques to ensure your system's security.

Important Notes:

Downloading applications from untrusted sources poses a significant security risk. Always exercise caution when installing new software.

Modifying Windows Security settings can impact system stability. Proceed with caution and create a system restore point before making significant changes.

With these steps, you should be able to effectively address the “This application cannot be blocked” message and protect your system from potential threats. If you need further assistance, feel free to consult a qualified IT professional for advanced troubleshooting and security guidance.