An unknown error happened within Windows.
In the More Info window expand the Details section. If the Scanner that failed was Windows Features please verify that the Windows Modules Installer service on the target computer is NOT disabled. If it is disabled, please re-enable it (it can be set to Manual) and retry the scan. If this does not resolve the issue, read on.
The cause of the error will depend on its error message and where the error occurred. This is often a problem with some corruption in the WMI Repository. If the error occurred while
Fix must take place on the target computer.
For Windows XP run
rundll32 wbemupgd, UpgradeRepository
For Windows 2003 run
rundll32 wbemupgd, RepairWMISetup
For Windows Vista, 7 and 2008 run
If the problem persists you may need to rebuild your WMI Repository. Here is a great article that I have used for years to fix my WMI problems.