I have a new Windows 8.1 laptop PC. Is the Microsoft Windows Defender anti-malware scanner that it uses by default sufficient or is there a better free scanner?

I have a new Windows 8.1 laptop PC. Is the Microsoft Windows Defender anti-malware scanner that it uses by default sufficient or is there a better free scanner? Microsoft has diminished the effectiveness of Windows Defender, which comes on new computers running Windows 8.1 so as not to compete with the third-party anti-malware companies. It…