How can I reinstall Windows security?

the screen like that

From admin PowerShell, run:

add-appxpackage -disabledevelopmentmode -register ((Get-AppxPackage Microsoft.SecHealthUI -allusers).InstallLocation + '\AppxManifest.xml')

The above command reinstalls Windows Security.

If that doesn't solve the issue, do the following and upload the respective logs.

Step 1:

• Download Farbar Recovery Scan Tool (FRST64.exe). [See also: Collect Farbar Recovery Scan Tool logs.]
• Rename FRST64.exe to EnglishFRST64.exe.
• Run EnglishFRST64.exe. Don't check or uncheck any options. Click "Scan".
• Upload the two logs, FRST.txt and Addition.txt, to your OneDrive and share the link here.

Step 2:

• Download defender_diag.bat. Right-click on the file, click Properties, Unblock, and OK. Run the batch file as administrator.

(The Batch file queries Defender-related settings/Policies and outputs the results to a log file named defender.log. Upload this log to your OneDrive and share the link here.)

(How-To: Share OneDrive files and folders - Microsoft Support)

Please try the fix here:

https://answers.microsoft.com/en-us/windows/forum/windows_11-security/i-cant-access-windows-security-its-just-a-blank/2f31ff62-8180-4523-8a7a-fb31350af4bf?messageId=349c35ed-9a38-4dd2-bab6-6ce29af31c8b

Download SecurityHealthSetup.exe

Ensure you right-click on the file and choose "Run as administrator"

File info:

• SHA256: F3607F433952CB23D9EB0FC5E31FD0C4079CAD3133DC79D149022900D208876C
• Virustotal: https://www.virustotal.com/gui/file/f3607f433952cb23d9eb0fc5e31fd0c4079cad3133dc79d149022900d208876c/detection

screen ilke that

Hello, how are you doing?

Welcome to the Microsoft community!

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I understand that you're facing difficulties with Windows Security, and I'm here to help you.

To reinstall and repair Windows Security, I recommend considering these three options in the following order:

Resetting Windows Security via Settings in Windows 11:

1. Open the Settings app directly or by pressing the Windows key + I.
2. Navigate to "Apps" in the left pane and select "Apps & Features" on the right.
3. Locate "Windows Security" and click on the three dots next to it.
4. Choose "Advanced options" from the context menu.
5. Click on the "Reset" option within the "Reset" section of Windows Security.

Resetting Windows Security may help resolve issues with the application. However, be aware that this process will reset Windows Security to its default settings, and you may need to reconfigure it after the reset.

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Using a PowerShell command:

*Before proceeding with this option, if you are using third-party antivirus or security software, you may need to disable it. Additionally, it's advisable to create a restore point as a precaution.

1. Begin by opening PowerShell as an administrator.
2. Run the following command:

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

3. Wait for the command to finish running.
4. To finalize the process, please restart your computer and check if the problem persists.

This command reinstalls the Windows Security user interface app (Microsoft.SecHealthUI) with the "-AllUsers" flag ensuring it's applied to all user accounts.

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Using a more advanced command:

1. Open PowerShell as an administrator.
2. Run the following command:

PowerShell -ExecutionPolicy Unrestricted -Command "& {$manifest = (Get-AppxPackage WindowsDefender).InstallLocation + '\AppxManifest.xml' ; Add-AppxPackage -DisableDevelopmentMode -Register -ForceApplicationShutdown $manifest}

3. Wait for the command to finish running.
4. Please restart your computer and check if the problem has been resolved.

The command reinstalls the Windows Defender application and registers it with Windows. It is more effective than other methods because it reinstalls the entire application, including all of its files and components.

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I hope this helps you.