
Fix 'Port Already Allocated' Error in Windows Defender on Windows 10
You may see an error like "Windows Defender Firewall cannot use port X because it is already allo...

You may see an error like "Windows Defender Firewall cannot use port X because it is already allo...

If the Windows Security app (Microsoft Defender) is missing, won’t open, or shows errors, reinsta...

You click Windows Security, and it just sits there spinning, never opening. This is a common frus...

You click "Check for updates" and see error 0x80072F0D or a message like "A certificate chain pro...

You see error 0x80070520 with the message 'The security token has expired.' This usually happens ...

You see an error that Windows Defender virus definition update failed. This usually happens when ...