If Windows Security (Microsoft Defender) throws Error 8024402f, Protection definition update failed on Windows 11, then follow this post to successfully fix the issue.

If you are not able to open Windows Security & you see error: Cannot Open this app, Your IT administrator has disabled Windows Security, see this post.

Users repeatedly report that "Windows Security" no longer starts. As this virus protection is integrated, this error should be rectified immediately.

On Windows 11 (and 10), if the Windows Security app isn't working, you can reset it in multiple ways to resolve the most common issues, and in this guide, I'll explain how.

Users may see a 0x800f0922 error when trying to install security update KB5012170 on the currently supported Windows operating system for consumers and the enterprise ...

Only go around the Windows 10 app block if you know for sure that the file is safe. How to open a file blocked by Windows Defender SmartScreen How to disable Windows Defender SmartScreen ...

Incorrect error messages seem to be a pattern for the company's latest operating system updates.