Click Start, type CMD in search.
From the results, right-click Command Prompt and Run as Administrator. Type the following command: (If you have logged in as Administrator, you can directly execute CMD)
When the system returns "WMI repository is not consistent" message, run the following command:[/list]
This will perform a consistency check on the WMI repository and resolve the issue. Restart the system, once done and try enabling Windows Defender program.