Windows Security Not Working

This started a few days ago & I have not been able to fix it.

I have 2 accounts on this computer:
1. Local Administrator - which is rarely used
2. Local Standard - which is regularly used

Whether I use the Start Menu icon, the Taskbar icon, Control Panel or the Settings App; Windows Security just will not open.
1. Using the Administrator account, Windows Security brings up a full blank blue screen, then closes w/in 2 seconds.
2. Using the Standard account, Windows Security does nothing at all.

I do get this message sometimes:


I've tried the 'Enable Windows Security for All Users' registry setting (Enable or Disable Windows Security in Windows 10) & although it does import & stays after a reboot, Windows Security still will not open.

I checked Services & see:
Security Center - Running - Automatic (Delayed Start)
Windows Defender Advanced Threat Protection Service - ___ - Manual
Windows Defender Firewall - Running - Automatic
Windows Security Service - Running - Automatic

Does anyone have any advice for me to get Windows Security working correctly again?

If the Windows Security app doesn't open, is crashing, or doesn't work properly, you can reset it to try to fix the Windows Security app.

Thanks for the reply & video. But unfortunately, it didn't help me.

When I clicked through Windows Security>More>App Settings, I get this Apps & Features page instead:


So I clicked through Settings>Update & Security>Windows Security & all I see is this:


When I click any of the choices from Open Windows Security to Family Options,
I get the "You'll need a new app to open this windowsdefender link" message again.

You can use attached batch script to reset Windows Security app in Windows 10.

I gave the Reset_Windows_Security.bat file a try, but that didn't help either.
Hopefully I'll think of/find a solution tomorrow, it's getting late here.

Have you tried Sfc /Scannow command?

You can also perform in-place upgrade of Windows 10. In-place upgrade is to use to replace the current operating system files on your computer. Unlike a clean installation of Windows, you can start a Windows in-place upgrade when your OS is still running. And an in-place upgrade can keep your files, settings, & apps during the upgrade process. You can perform a Windows 10 in-place upgrade is to use the Windows 11 Media Creation Tool. Make sure to select Upgrade this PC now and click Next. Follow the on-screen guide to perform a Windows 10 in-place upgrade.

Repair Install Windows 10 with an In-place Upgrade

How to Fix You’ll Need a New App to Open This Windowsdefender Link Windows 11/10

CJW said:

Thanks for the reply & video. But unfortunately, it didn't help me.

When I clicked through Windows Security>More>App Settings, I get this Apps & Features page instead:


So I clicked through Settings>Update & Security>Windows Security & all I see is this:


When I click any of the choices from Open Windows Security to Family Options,
I get the "You'll need a new app to open this windowsdefender link" message again.

Follow FreeBooter's instructions in post #6.

I ran the command Sfc /Scannow & below is what came back:


I looked at the CBS.log file & it hurt my head. It's long (w/dates between 7/29 & 8/5 at over 62,500 lines!). Needless to say, I did not read all 62,500+ lines & what I did read, I can't make much sense from it.
And what is the OFFLOGFILE flag?

I wonder if those "corrupt" files have anything to do w/the tweaks, patches & App removals I've done that Microsoft doesn't think we should do to OUR computer OS & other software.

I think it may be better/easier for me to reinstall Windows 10. I was planning to later this year anyway.

CJW said:

I ran the command Sfc /Scannow & below is what came back:


I looked at the CBS.log file & it hurt my head. It's long (w/dates between 7/29 & 8/5 at over 62,500 lines!). Needless to say, I did not read all 62,500+ lines & what I did read, I can't make much sense from it.
And what is the OFFLOGFILE flag?

I wonder if those "corrupt" files have anything to do w/the tweaks, patches & App removals I've done that Microsoft doesn't think we should do to OUR computer OS & other software.

I think it may be better/easier for me to reinstall Windows 10. I was planning to later this year anyway.

Execute Dism /online /cleanup-image /restorehealth command and when it finished execute Sfc /scannow command.