Windows Defender win8 can not be closed under the solution

Recently, Xiaobian pre-installed Windows 8 models, click Windows Defender software under the Metro interface. Tip:
“Windows Defender is closed and will not monitor your computer.”
Unable to open Windows defender, how to deal with the following figure:?


analysis:
Windows defender is Microsoft's own antivirus anti-spyware software, when installed on our machines other antivirus software, such as:
Mcafee, After 360, Jinshan, Kaspersky and other third-party anti-virus software, Windows defender will be automatically disabled.
Solution:
Take Y400/Y500 as an example:
The pre-installed anti-virus software for this model is Mcafee.
Step 1: Uninstall Mcafee in the control panel, as shown below:

Step 2: After restarting the machine according to the prompt, go to “Control Panel” "System Security”“Operation Center”&ldquo ;Security"Click “Immediately enable”
Windows defender. When enabled, the “Update Now” button will be displayed. Windows defender is now open:
As shown below: