How to Fix Youll Need a New App to Open This Windows Defender Error

Resolving the “You’ll Need a New App to Open Windows Defender” Error

We’ve all been there – excited to try out a new Windows feature, only to be met with an error message. One common error on Windows 10 and 11 is "You’ll need a new app to open this Windows Defender." This confusing message blocks access to the vital Windows Security app, leaving your system vulnerable. Not to worry, as this post covers multiple methods to resolve this issue for good.

Why Does This Error Occur?

There are a few potential culprits for this Windows Security error:

Corrupted system files from updates or other issues
Conflicts from third-party antivirus software
An outdated Windows version not supporting Security app
Improperly configured Windows Security app settings
Missing or corrupted Windows Security app files

To pinpoint the cause, we’ll need to try several troubleshooting steps.

How do I Reset my Windows 10 security settings?

Click on the search icon on the taskbar and type Windows security. Click on App Settings. Scroll down and click on Terminate followed by Reset. Was this reply helpful? Thank you. It didn’t work this way, I don’t know why, but it sure worked through elevated Powershell. Was this reply helpful?

How do I Reset my Windows 11 security app?

Step 1: Press the Windows key + I to open the Settings app. In the System tab, click on Recovery. Step 2: Click the Reset PC button. Step 3: Select the Keep my files option and then follow the on-screen prompts to finish resetting Windows 11. After Windows 11 resets everything, the Windows Security app should work as before. 1.

1. Restart Your PC

The simplest initial step is a restart. This clears any memory issues and reloads all Windows apps cleanly.

Click the Start button and choose Power > Restart.
After rebooting, try to open Windows Security again.

If the error persists, move on to updating Windows next.

2. Update Windows

An outdated Windows build can trigger compatibility issues and bugs.

Open Settings > Update & Security > Windows Update
Click Check for updates. Install any available updates.
Restart your PC when prompted.
After rebooting, attempt to reopen Windows Security.

Updating brings Windows to the latest stable version with bug fixes. If you still see the error, corrupted files may be the cause.

3. Run SFC and DISM Scans

Corrupted system files can prevent apps like Windows Security from opening. To scan for errors, use the System File Checker (SFC) and Deployment Image Servicing and Management (DISM) tools.

From an admin Command Prompt:

TypeSFC /scannowto scan system files and repair issues
RunDISM /Online /Cleanup-Image /RestoreHealthto fix corrupt OS images
Rerun SFC after DISM finishes
Restart your computer once done

This repairs crucial operating system files. Running SFC and DISM scans before troubleshooting other aspects often resolves many common Windows issues.

How do I check if my computer has a virus?

If you suspect there’s malware or a virus on your device, you should immediately run a quick scan. Note: Because of streamlined security, this isn’t available if you’re running Windows 10 or 11 in S mode. Select Start > Settings > Update & Security > Windows Security and then Virus & threat protection.

How do I fix Windows 10 security issues?

Press Win + I to open Settings. On the left-hand pane, click on “Windows Update” at the bottom of the list. Click on the “Check for updates” button to see if there are pending updates. Proceed to install updates if your PC isn’t up-to-date. After your PC restarts, check to see whether the issue with Windows Security is resolved. 6.

4. Repair or Reset Windows Security

If system file scans come back clean, next try repairing or resetting the Windows Security app itself.

To repair the app:

Open Settings > Apps > Apps & features
Locate Windows Security in the list
Click Modify
Choose Repair from the menu
Restart your PC after it completes

Resetting restores the app to original settings:

In Apps & features, select Windows Security
Click Advanced options
Select Reset
Restart your computer once done

Repairing fixes corrupt app files while resetting clears out any bad configurations or settings.

5. Uninstall Third-Party Antivirus Software

Third-party antivirus tools like McAfee and Norton can block access to Windows Security. If you have another antivirus program installed, temporarily uninstall it and restart your computer.

Then see if the Windows Security error has gone away. Reinstall your desired antivirus again afterwards if needed.

6. Re-register Windows Security Via PowerShell

As a last resort, you can re-register the Windows Security app using PowerShell commands.

How do I fix Windows security problems?

Follow these steps to automatically diagnose and repair Windows security problems by turning on UAC, DEP protection, Windows Firewall, and other Windows security options and features. Select the Download button on this page. In the File Download dialog box, click Run or Open, and then follow the steps in the Windows Security Troubleshooter.

How do I fix Windows Security on Windows 10?

To repair Windows Security, press the Win key + S to open Windows Search and type windows security in the search box. In the search results, under Best match, right-click Windows Security and select App settings. Scroll down until you get to the Reset section and click on Repair.

Launch an elevated PowerShell and run:

Add-AppxPackage -Register -DisableDevelopmentMode "C:\Windows\SystemApps\Microsoft.Windows.SecHealthUI_cw5n1h2txyewy\AppXManifest.xml"

This will re-register the necessary app files for Windows Security. Combined with the earlier solutions, this should resolve the issue for good.

Prevent This Error Going Forward

While frustrating, this Windows Security error can be fixed with the right troubleshooting steps. To avoid potential reoccurrences:

Keep Windows updated
Run regular SFC and DISM scans
Don’t install unsupported third-party antivirus tools
Backup system files and the Windows Security app

Following these tips will maintain a healthy Windows environment and prevent this error from ruining your day again. Let us know if any other Windows-related issues pop up!

References

How does Windows 10 protect my device?

Your device will be actively protected from the moment you start Windows 10. Windows Security continually scans for malware (malicious software), viruses, and security threats. In addition to this real-time protection, updates are downloaded automatically to help keep your device safe and protect it from threats.

How to repair windows 11 security?

How to Repair Windows Security in Windows 11? Press the Win+I key on the keyboard to open Settings. On the next page, click on the button in Settings. Click on to confirm. When you reset Windows Security, everything from your security key will be deleted and reset to factory defaults. All data and credentials will be cleared.

How do I reinstall Windows Security on Windows 10?

Step 1: Press the Windows key + S to open the search menu. Type powershell and select Run as Administrator from the right pane. Step 2: Select Yes when the User Account Control (UAC) prompt appears. Step 3: Paste the following command in the console and press Enter. Exit the PowerShell window and try to use the Windows Security app again. 3.

How do I hide a virus in Windows 10?

Expand the tree to Windows components > Windows Security > Virus and threat protection. Open the Hide the Virus and threat protection area setting and set it to Enabled. Select OK. Deploy the updated GPO as you normally do. If you hide all sections then Windows Security will show a restricted interface, as in the following screenshot: