How do I block unwanted apps on Windows 10?

Windows 10 will begin blocking “potentially unwanted applications”—bundled apps that you probably don’t want—by default, Microsoft says, beginning in early August. The change was announced in a support document noted by Windows Latest. 

If you download a lot of third-party utilities, you may already have run into a potentially unwanted application (PUA), also called a potentially unwanted program (PUP). The terms most often describe a bundled piece of adware, or—worse—a small additional application that slowly mines cryptocurrency in the background.

You might not even know where the PUA comes from. Sometimes it might be the developer itself that added the PUA for additional revenue, or a site that aggregates the utilities and provides them for download. Either way, the PUA is an app you never asked for and probably don’t want.

Microsoft is becoming slightly more aggressive in how it treats PUAs. Microsoft already offered you the capability of automatically filtering PUAs as part of the Windows 10 May 2020 Update, though it was off by default. “Starting in early August 2021 we’ll begin turning it on by default to make it easier for you to keep your systems performing at their best,” Microsoft says.

Filtering apps, of course, can lead to errors. After all, you might want to download a cryptominer to generate a bit of extra income, or an app that distributes updates via an attached BitTorrent client that you’re aware of and accept. If that’s true, you can still toggle what Microsoft calls “reputation-basd protection” on and off inside the Windows 10 Settings menu. Go to the Windows Security app via the Windows 10 Settings menu or Windows 10 search box, then to App & browser control > Reputation-based protection. 

Here’s where you can find the Windows 10 reputation-protection settings.

Under Potentially unwanted app blocking you’ll see two toggle options, Block apps and Block downloads. Both have similar functions. Block downloads works at the browser level, but only with Microsoft Edge. Block apps would be used to fend off apps before download within Chrome or another browser, because Windows Defender will examine those apps only after they’ve been downloaded.

You’ll also see a “master” toggle switch to turn of reputation-based protection entirely, though it’s not recommended. As of this month, the reputation-based protection will be on by default.

Microsoft will quarantine the PUA if it detects it. There, you’l have the option to delete it, leave it in an isolated “quarantine” state or allow it on your system.

Note that turning on Block apps or Block downloads won’t block all apps or downloads, just the ones that Microsoft deems suspicious. Microsoft will quarantine any PUAs it detects and let you choose whether to go ahead and install it on your device. Microsoft is simply using what it knows about the app to let you know gently that it might not be a good idea.

Author: Mark Hachman, Senior Editor

As PCWorld's senior editor, Mark focuses on Microsoft news and chip technology, among other beats. He has formerly written for PCMag, BYTE, Slashdot, eWEEK, and ReadWrite.

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.

• Enable potentially unwanted apps blocking on Windows 10
• View blocked potentially unwanted apps history on Windows 10
• Disable potentially unwanted apps blocking 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

   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

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

4. Under the “Potentially unwanted app blocking” section, click the Protection history option.

   
   
   PUA protection history option

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

   
   
   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

4. Under the “Potentially unwanted app blocking” section, turn off the toggle switch.

   
   
   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.

How do I stop unwanted programs?

How do I find unwanted programs in Windows 10?

Where can I find Potentially Unwanted Programs?