How to fix \\?\C:\Windows\System32\SecurityHealth\10.0.29510.1001-0\SecurityHealthSS).dll

Hello Cal, I’m Henry, and I’d like to help you with this issue.

It looks like the problem may be related to the SecurityHealthSSO.dll file on your computer. To fix this, we’ll replace it with a fresh copy. Please follow these steps carefully:

1. Create a folder named Temp on your C: drive (e.g., C:\Temp).
2. Download SecurityHealthSSO.dll and save that file in folder Temp.
3. Open Command Prompt as Administrator and run the following commands:
   • cd /d C:\Windows\System32\SecurityHealth\10.0.29510.1001-0
   • takeown /f SecurityHealthSSO.dll /a
   • icacls SecurityHealthSSO.dll /grant *S-1-5-32-544:(F)
   • Copy the new DLL file from the Temp folder to overwrite the old one: copy /y C:\Temp\SecurityHealthSSO.dll
4. Once complete, restart your computer.

Here is the relevant command screenshot. You can try it by replacing the error path with the version number 10.0.29510.1001-0

I hope you’ll give my recommendation a try and let me know how it goes or can help me post the screenshot of the Command Prompt window and if this answer helps, feel free to hit “Accept Answer” so others can benefit too.

Hello Cal,

This 0xC000012F popup is a Bad Image condition error: Windows is trying to load a Windows Security DLL that’s corrupted or version-mismatched, so the component fails at startup. Please try the following workaround:

1. Update the Windows Security platform

Run Windows Update and install all pending updates (including optional/defender/security platform items), then reboot.

2. Re-register/repair the Windows Security app

Open PowerShell (Admin) and run:

Get-AppxPackage Microsoft.SecHealthUI | Reset-AppxPackage

This targets the Windows Security UI layer that often breaks alongside the SecurityHealth DLL issue.

3. Replace the broken DLL in the exact folder

• Place a copy of the same DLL name (exactly as shown in your popup) at *C:* (example: C:\SecurityHealthSSO.dll) from a healthy computer.
• Open Command Prompt (Admin) and run (adjust the DLL name to match your error):

takeown /f "C:\Windows\System32\SecurityHealth\10.0.29510.1001-0\SecurityHealthSSO.dll" /a
icacls "C:\Windows\System32\SecurityHealth\10.0.29510.1001-0\SecurityHealthSSO.dll" /grant administrators:F
copy "C:\SecurityHealthSSO.dll" "C:\Windows\System32\SecurityHealth\10.0.29510.1001-0\"

This mirrors the accepted fix pattern: take ownership → grant permissions → overwrite the DLL.

I hope you've found something useful here. If it helps you get more insight into the issue, it's appreciated to accept the answer. Should you have more questions, feel free to leave a message.

Have a nice day!