How to block potentially malicious apps on Windows 10

Windows 10 May 2020 Update ships with a new feature to protect against potentially unwanted apps, and here's how to enable the feature.

Block malicious apps on Windows 10
Block malicious apps on Windows 10

On Windows 10, in addition to the Microsoft Defender Antivirus to protect your device and files from viruses, ransomware, spyware, and other forms of malware, starting with the May 2020 Update (version 2004), Windows Security is introducing a new feature to protect your system against unwanted apps.

The feature is known as Potentially Unwanted Applications (PUA) blocking. Once enabled, it can detect and block low-reputation apps that may cause unexpected behaviors on Windows 10, such as poorly designed apps or apps designed to cause harm.

In this guide, you will learn the steps to enable (or disable) the protection against potentially unwanted apps using the Windows Security app on Windows 10.

Quick note: Starting August 2021, Microsoft is enabling Potentially Unwanted Applications by default on all Windows 10 devices. However, you’re still in control, and you can always enable or disable the feature with these instructions.

Enable potentially unwanted apps blocking on Windows 10

To block potentially unwanted apps on Windows 10, use these steps:

  1. Open Windows Security.

  2. Click on App & browser control.

  3. Click the Reputation-based protection settings option.

    Reputation-based protection settings
    Reputation-based protection settings
    Quick tip: You can also click the Turn on button to enable PUA protection (if available).
  4. Under the “Potentially unwanted app blocking” section, turn on the toggle switch.

    Enable potentially unwanted apps on Windows 10
    Enable potentially unwanted apps on Windows 10
  5. (Optional) Clear the Block apps option if you only want protection from unwanted downloads.

  6. (Optional) Clear the Block downloads option if you only want protection from unwanted app installations.

Once you complete the steps, Microsoft Defender Antivirus will monitor and block apps with a bad reputation and those that might cause unexpected behaviors, such as poorly code apps, adware, cryptocurrency miners, and more.

View blocked potentially unwanted apps history on Windows 10

To view blocked malicious apps history, use these steps:

  1. Open Windows Security.

  2. Click on App & browser control.

  3. Click the Reputation-based protection settings option.

    Reputation-based protection settings
    Reputation-based protection settings
  4. Under the “Potentially unwanted app blocking” section, click the Protection history option.

    PUA protection history option
    PUA protection history option
  5. Confirm the apps that have been blocked by PUA protection.

    PUA protection history
    PUA protection history

After you complete the steps, you’ll be able to see the apps that the antivirus has blocked using the protection feature.

Disable potentially unwanted apps blocking on Windows 10

To prevent Windows 10 from blocking potentially unwanted apps, use these steps:

  1. Open Windows Security.

  2. Click on App & browser control.

  3. Click the Reputation-based protection settings option.

    Reputation-based protection settings
    Reputation-based protection settings
  4. Under the “Potentially unwanted app blocking” section, turn off the toggle switch.

    Disable potentially unwanted apps on Windows 10
    Disable potentially unwanted apps on Windows 10

Once you complete the steps, PUA protection will disable from Windows 10.                                                         

Alongside the ability to block malicious and poorly coded apps with Windows Security, Microsoft Edge also include a similar feature that you can enable from the privacy and services settings.

About the author

Mauro Huculak is a Windows expert and the Editor-in-Chief who started Pureinfotech in 2010 as an independent online publication. He is also been a Windows Central contributor for nearly a decade. Mauro has over 12 years of experience writing comprehensive guides and creating professional videos about Windows, software, and related technologies, including Android and Linux. Before becoming a technology writer, he was an IT administrator for seven years. In total, Mauro has over 20 years of combined experience in technology. Throughout his career, he achieved different professional certifications from Microsoft (MSCA), Cisco (CCNP), VMware (VCP), and CompTIA (A+ and Network+), and he has been recognized as a Microsoft MVP for many years. You can follow him on X (Twitter), YouTube, LinkedIn and About.me.