
Windows Defender Authentication Failed: Step-by-Step Checklist
You open Windows Security and see 'Authentication failed' when trying to use Windows Defender. Th...

You open Windows Security and see 'Authentication failed' when trying to use Windows Defender. Th...

You log in to Windows, and immediately get a prompt to enter your Microsoft account password or P...

You open Windows Security and see an error about a dependency conflict—maybe a service failed to ...

You click the Windows Security icon in the taskbar or try to open it from Settings, but nothing h...

If Windows Update is stuck at a certain percentage or taking forever to check for updates, a corr...

You try to install or enable a Chrome extension and see an 'Access denied' message. This can happ...