One for the googlebots really as I’ve just cured it 
Brand new laptop, first thing I had to do was uninstall “Norton security” :rolleyes: and then I put Avast on. There after I had vista security center reporting that defender wasn’t working, when I hit the button to start it it would report that “there are no updates” and that it still wasn’t working, yet if i went to control panel>defender it seemed to be working correctly. Also had Avast installed yet it also reported that I had no anti virus installed.
Lots of net searching revealed this fix 
Run a cmd prompt as administrator.
type the following command: winmgmt /verifyrepository
if the system returns “WMI repository is not consistent”
run this command: winmgmt /salvagerepository
The first time you run this it will fail. It will issue stop commands to
the services causing it to fail. It might take a couple minutes for the
services to shut down. Run the command again. I actually ran it 3 times
before it finally ran and completed on its own.
Reboot your system.
