My PC Windows security is displaying "Page not available" out of the blue

Question

My PC Windows security is displaying "Page not available" out of the blue

Olafusi Samuel 0

Screenshot 2026-08-31 140443.png

I opened my PC 2 days ago and couldn't access this window again, i have applied every possible solution online but all to no avail. kindly help me with this issue.

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Answer 1

David-M 125K Independent Advisor

Hi. I'm David, and I'm happy to help you.

To be able to assist you better, please clarify the following:

Do you have, or have you ever had, third-party antivirus software installed? If so, which one?

Also. What is the current "OS Build" of your Windows 11?

Press "Windows + R", type winver, and click OK.

If you prefer, share a screenshot. Use the shortcut "Windows + Shift + S" to use the screenshot tool.

Be sure to censor your email address if it appears. The Microsoft Q&A is public.

Looking forward to your reply.

Olafusi Samuel 0 Reputation points

2026-08-31T13:50:46.26+00:00

This is my windows OS build and I have never installed a third party antivirus software on my PC
David-M 125K Reputation points Independent Advisor

2026-08-31T14:05:48.43+00:00
Thanks for the clarifications.

Do you have any work or school account connected to Windows?

Also, please do the following:

Press "Windows + R", type regedit and press Enter;

Navigate to the following key:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender

Take a screenshot of the right panel;

(Use the shortcut "Windows + Shift + S" to use the screenshot tool.)

Then, navigate to the following key:

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender Security Center

Take a screenshot of the right panel;

(Note: If any of these keys/folders do not exist in your registry, don't worry; just let me know.)

Then, share the screenshots.

Looking forward to your reply.

Feel free to ask any questions you may have.
Olafusi Samuel 0 Reputation points

2026-08-31T18:48:05.24+00:00

I had a school account connected before but when the issue started, one of the resolution i went through was to remove it.

This is the screenshot for the first

This is the screenshot for the second
David-M 125K Reputation points Independent Advisor

2026-08-31T18:58:26.7966667+00:00
Thanks for the clarification and screenshots.

Do the procedure below and see if you can open Windows Security correctly:

Press "Windows + X" and select "Terminal (Admin)";

Type or paste the following command and press Enter:

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

Restart (not shutdown) your PC.

If it persists, I suggest you do the procedure below:

Press "Windows + X" and select "Terminal (Admin)";

Type or paste the following command and press Enter:

Get-AppXPackage -AllUsers | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register "$($_.InstallLocation)\AppXManifest.xml"}

Note: Several red warnings may appear when running this command. Ignore them. It's normal.

Wait for the procedure to finish, and restart (not shutdown) the PC.

If the problem persists, please let me know, and I will provide another method.

Feel free to ask any questions you may have.
Olafusi Samuel 0 Reputation points

2026-08-31T19:42:22.1033333+00:00

The problem still persists
Olafusi Samuel 0 Reputation points

2026-08-31T19:46:21.13+00:00

I don't know if the issues related to this windows update issue, the two started around same time, but this windows update keeps displaying different error code after different failed installation session, currently this is the error code displayed
David-M 125K Reputation points Independent Advisor

2026-09-01T11:57:30.2333333+00:00
Sorry for the delay in reply. I've been offline.

I am not sure if the issue with Windows Security is directly related to the error you received in Windows Update. I have seen failed Windows updates cause other system problems that ceased once the update issue was resolved. Therefore, I think it is a good idea to check this before trying another procedure focused on Windows Security.

The update in your screenshot is a "Preview" update, essentially a beta version of the update scheduled for release next month. Preview updates are optional and may include experimental fixes or features. Because they haven't undergone full testing, they can sometimes be unstable or fail to install properly. Importantly, you're not required to install preview updates, and skipping them won't expose your system to any security risks.

I suggest you prevent Windows from attempting to install preview updates by doing the following:

Press "Windows + I" and select "Windows Update";

Toggle off "Get the latest updates as soon as they're available";

Restart (not shutdown) your PC.

This will stop Windows from downloading optional updates like previews, and your system will only receive standard monthly updates going forward.

After doing this, check if Windows Update displays only the message "You're up to date".

If everything looks good in Windows Update, check if Windows Security loads correctly.

Please let me know how it goes.

Feel free to ask any questions you may have.