Try to force a rebuild of the repository, monitored security software
usually show back up then. All of these commands are typed in manually at a
command prompt (Accessories menu). Run as administrator.
Method 1:
winmgmt /verifyrepository
If WMI repository is reported to be inconcistent, run the following command:
winmgmt /salvagerepository
Method 2:
net stop winmgmt /y
cd %windir%\system32\wbem\
ren repository repository.old
Then restart.
For more information on winmgmt, type 'winmgmt /?' without the quotes.