CNET writes Microsoft has decided to offer built-in malware protection in Windows 8:
At a demo of Windows 8's security at Microsoft's Build conference on Tuesday posted by The Register, Steven Sinofsky, president of the Windows and Windows Live division, said that "we've taken Defender, and we've actually built a whole new range of protection, all the way up through anti-malware, antivirus, all that is built into Defender."
Beyond strengthening Defender, Microsoft is working to improve security from the boot level.
The demo at Build revealed a new feature called Secured Boot. Michael Angiulo, corporate vice president of Windows Planning and Ecosystem, showed off the feature by trying to boot up a computer with an infected USB stick. Instead of loading Windows, the computer detected the malware, stopped the boot process, and displayed a warning message that the system had been compromised.