If you experience problems with Windows defender (“Windows security”), it may help to reinstall this protection.
Some users experience problems starting Windows Defender, for example after uninstalling antivirus software. Problems are also reported too often with one Windows defender link error message.
To resolve problems with Windows Defender, you can reinstall Windows Defender. Even though Windows Defender is a standard part of Windows 11 and Windows 10 you cannot reinstall this protection through the settings.
If you windows defender To reinstall you must use PowerShell. This is a scripting language that restores certain functions in Windows in the background, including the Windows defender function.
Reinstall Windows Defender in Windows 11 or Windows 10
To reinstall Windows Defender you need: administrator rights required in Windows. Make sure you are logged in with one administrator account.
Right-click on the Start button. Click on "Windows Terminal (administrator)” or “PowerShell (admin)” in the menu.
We'll go first Set PowerShell to a policy so that all scripts can be run. This prevents the code needed to reinstall Windows Defender cannot be executed.
In the PowerShell window copy and paste the following code:
Set-ExecutionPolicy Unrestricted
Then copy and paste the following code:
Get-AppXPackage -AllUsers | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}
You will now see blue text with lines of code running. Sometimes you will see a red error message in between saying “Add-AppxPackage : Deployment failed with HRESULT: 0x80073D02, The package could not be installed because resources were
changes to be made are currently in use.';
This is no problem at all. This means that packages being installed are already in use. The code continues as normal, waiting for the process to complete.
After the code has been executed, reset the policy as it was. Copy and paste the following code:
Set-ExecutionPolicy Default
Now open Windows Defender again. You will see that Windows Defender (“Windows Security”) has now been successfully reinstalled.
I hope this helped you. Thank you for reading!
Also read:
Hello, I have implemented your tip but I still have the problem that in the Windows security screen I see a completely white screen and on the left only the <- the 3 horizontal stripes and house start
otherwise the screen is completely white
What can I do now to fix this?
I also tried to install an external virus scanner (avast free) for testing, but that also gives an error message, so I don't know anymore.
Hello, you can reset “Windows Security”.
Search for “Windows security” via the taskbar. Right-click on the result. In the menu, click on “App Settings”. Then click “Reset”. Now restart your computer.
Now check whether Windows security is working properly.
Success!
Stefan, Unfortunately this has had no effect. I keep that blank page and cannot do anything else with it
Hello, I suspect from your previous posts that there are other problems. You indicate that Avast also gave an error message during installation, what I would do is reset Windows 10 while retaining files:
https://support.microsoft.com/nl-nl/windows/geef-uw-pc-een-nieuwe-start-0ef73740-b927-549b-b7c9-e6f2b48d275e#ID0EBD=Windows_10
Success!
After reinstalling Windows Defender it works again!
Thank you
Wim
Glad it worked out. Thanks for your response! 🙂
Microsoft Defender starts up every morning that I have to run the quick scan?
I have tried everything, but I always have to do the quick scan again
What can be done about this???
BV thanks
Wim
Hello, this could be due to apps installed on your computer, which trigger a scan. CCleaner is notorious for this. You can also check whether a scheduled scan has been set:
https://support.microsoft.com/nl-nl/topic/een-scan-in-microsoft-defender-antivirus-plannen-54b64e9c-880a-c6b6-2416-0eb330ed5d2d
Success!