I can't laugh and cry: Exploring the built-in anti-virus software

in Windows 8 A long time ago, there was a rumor that Microsoft would put anti-virus software in Windows 8. When the news was released, the bosses of the world who are doing Windows system security are sweating at the soles of their hands.
A few days ago, at 8:00 am on September 14th, Beijing time, China officially opened the Windows 8 developer preview version of the download to the world. Many security industry people also downloaded Windows 8 after the first time. Taking a breath, fortunately, it seems that there is no Microsoft Free Anti-Virus (MSE) placement.
Searching for MSE in Windows 8, the results are all 0.

But, the good guys later unveiled a mystery. Originally, MSE, the Microsoft free anti-virus software, was built in Windows 8, and it quietly replaced the previous Windows Defender.
When we ran Windows Defender in the Windows 8 Developer Preview, the amazing scene appeared -

There was a silence around me.
Microsoft, in this way, replace MSE with Windows Defender in Vista and Win7 era, Microsoft free anti-virus software is officially built in Win8.
Remember that there is Windows Update within 24 hours after installing Windows 8?
Now I finally understand, it is a virus database update.