The built-in security solution of Windows 8, Windows Defender, managed to detect only half of the malicious code samples thrown at it in a very basic test by Chester Wisniewski, a senior security advisor at Sophos Canada.

Wisniewski revealed that he installed the Windows Developer Preview in a virtual machine and tested it against a selection of Windows, Mac OS X and Linux malware.

The conclusion? Wisniewski stresses that the Windows 8 antivirus still has a long way to go.

Windows 8 AV Detected Only 50% of Malware Samples Thrown at It, Says Sophos - Softpedia

I dont believe in everything i read. I like MSE