Malware Protection issues in Security Center

Hi,

I'm having some issues with the Malware Protection in Security Center.

First, any of the anti-virus programs I've installed are detected by the
"Security Centre". I am using MacAfee.

Second, I can't turn on Windows Defender in the Security Center. When I try
to activate it, he searches for any available update. Once he detects it is
up to date, a warning message window pops-up and there's no way to turn it
on.

Because of these two issues, I'm continuosly getting alerts from the
Security Center. And I know that both programs are up and running.

Could you help me figuring out as to how to get rid of these Security Center
Alerts.

Cheers