Here are procedures to correct the WMI repository that causes the Windows Security Center to report that no antivirus, antispyware, or firewall is active, yet OneCare is actively protecting your PC and in green status.
When running this in Vista, you must run the procedures as an administrator, elevated.
Scroll down to Windows Management Instrumentation and double-click it. Now click on the "Pause" button. Leave that window open and double-click My Computer. Navigate to %systemroot%\Windows\System32\wbem (where %systemroot% is the drive where XP is installed). Delete the Repository folder and *only* the Repository folder. Now go back to the WMI service window you left open and restart the service.
This will rebuild the Repository and hopefully straighten out the incorrect entries for all your duplicates.
In order to see the Windows files, you may need to unhide them:
Make sure you are able to see all hidden files and extensions (View tab in Folder Options).
Check "Display the contents of system folders".
Check "Show hidden files and folders".
Uncheck "Hide protected operating system files" and click "OK" to the dialog box.
Method B from MVP Torgeir Bakken (more elegant)
Open a command window (Start/Run --> cmd.exe) and run the following commands:
net stop winmgmt cd /d %windir%\system32\wbem ren repository repository.old (or delete it using the command "rd /s repository" instead of the ren command) net start winmgmt
It may take a minute or so to complete while WMI rebuilds the database.