HOW TO FIX the Windows Security Center error:

You'll need a new app to open this windowsdefender link

Look for an app in the Microsoft Store

ITNU - computer help - You need an app to open this

This is quite a common issue that we have encountered in Windows 11. It seems some Anti-Virus break Microsoft Defender.

If you get the error “You’ll need a new app to open this windowsdefender link” when you attempt to open the Windows Security icon on the taskbar. 

Restart your computer.

Close all applications.

Click start and start typing “powershell”

When “Windows Powershell appears”, right click and RUN AS ADMINISTRATOR

When the powershell command prompt opens, type this: 

Get-AppxPackage Microsoft.SecHealthUI -AllUsers | Reset-AppxPackage

When it has completed, exit. Then restart Windows.

It should fix this issue after the restart.

 

More detailed instructions / alternatives:

On windows 11 do this

  1. launch powershell as an administrator
  2. Set-ExecutionPolicy Unrestricted
  3. Get-AppXPackage -AllUsers | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register “$($_.InstallLocation)\AppXManifest.xml”}
  4. Set-ExecutionPolicy restricted
 

IGNORE THE ERRORS

On Windows 10 do this:

  1. launch powershell as an administrator
  2. run get-AppxPackage Microsoft.SecHealthUI -AllUsers | Reset-AppxPackage
 

if it doesn’t work type this in the PowerShell prompt:

  1. Add-AppxPackage -Register -DisableDevelopmentMode “C:\Windows\SystemApps\Microsoft.Windows.SecHealthUI_cw5n1h2txyewy\AppXManifest.xml”
  2. Get-AppxPackage Microsoft.SecHealthUI -AllUsers | Reset-AppxPackage