How to Remove Potentially Unwanted Programs Detected by Microsoft Defender

Meta description: Remove PUPs flagged by Defender before they cause ads or slowdowns, and use Kudu to help review unwanted software.

What Causes This?

Potentially Unwanted Programs, or PUPs, usually get installed alongside free apps, browser downloads, fake update prompts, or aggressive “system cleaner” tools. They are not always full malware, but they can still add ads, change browser settings, install background services, or slow down your PC.

Microsoft Defender flags these apps when it detects behavior that is misleading, intrusive, or commonly bundled without clear consent. In some cases, the program is already installed; in others, Defender blocks it before it finishes setting itself up.

Common Symptoms

• Microsoft Defender shows a warning about a potentially unwanted app
• Your browser homepage, search engine, or new tab page changes unexpectedly
• Pop-ups, ads, or notifications appear more often than usual
• Your PC feels slower or starts unknown apps in the background
• You notice unfamiliar programs in the installed apps list

How to Fix It Manually

1. Review the Defender alert

   • Open Windows Security from the Start menu.
   • Click Virus & threat protection.
   • Under Current threats or Protection history, find the detection marked as a potentially unwanted app.
   • Click the item to see its name, affected file, and recommended action.

2. Remove or quarantine the detected item

   • In the same Defender alert, choose Remove if available.
   • If you want to isolate it first, choose Quarantine.
   • Restart your PC after Defender finishes the action, especially if the alert mentioned a running process or startup item.

3. Uninstall the related program from Windows

   • Press Windows + I to open Settings.
   • Go to Apps > Installed apps on Windows 11, or Apps > Apps & features on Windows 10.
   • Sort by Install date or search for the app name shown in Defender.
   • Select the suspicious program and click Uninstall.
   • Also remove any unknown toolbars, “PC optimizer,” “driver updater,” coupon apps, or download managers you did not intentionally install.

4. Check browser extensions and settings

   • In Microsoft Edge, open the menu with Alt + F and go to Extensions > Manage extensions.
   • Remove any extension you do not recognize.
   • Then go to Settings > Privacy, search, and services and review your default search engine and startup pages.
   • If you use Chrome, open chrome://extensions and remove suspicious add-ons there too.

5. Disable suspicious startup apps

   • Open Task Manager with Ctrl + Shift + Esc.
   • Click the Startup or Startup apps tab.
   • Look for unknown entries, especially ones matching the PUP name or publisher.
   • Right-click the item and choose Disable.
   • This helps stop leftover components from relaunching after reboot.

6. Run a full Defender scan

   • Open Windows Security > Virus & threat protection.
   • Click Scan options.
   • Choose Full scan, then click Scan now.
   • If Defender finds more items, remove them and restart again.
   • After the scan, check Protection history to confirm the threat was cleared.

7. Turn on PUA protection if it is off

   • In Windows Security, go to App & browser control > Reputation-based protection settings.
   • Make sure Potentially unwanted app blocking is turned On.
   • Enable both Block apps and Block downloads if available.

Fix It Automatically with Kudu

Kudu can help you quickly review installed software, startup items, and other common clutter that often comes with PUPs. It gives you an easier way to spot unwanted programs and clean up the leftovers that Defender may not fully organize for you.

Download Kudu Free →