If You'll need a new app to open this windowsdefender link message appears every time you open Windows Defender, see this post.

If Windows Defender is missing and is gone or has disappeared in Windows 11/10, here are some suggestions that are sure to help you resolve the issue.

For Windows 10 users, there's a built-in antivirus protection program called Microsoft Defender Antivirus. Here's what you need to know.