You receive a COMException error or another error indicating an unknown error happened within Windows.
In the More Info window, expand the Details section. If the PDQ Inventory scanner that failed was Windows Features please verify that the Windows Modules Installer service (TrustedInstaller) 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, the cause of the error will depend on its error message and where the error occurred (check Event Viewer for additional information regarding the error). This is often a problem with some corruption in the WMI Repository.
To repair the WMI Repository, run the following command from an administrative/elevated command prompt on the target machine. While the command may return fairly quickly, the actual rebuild process can take around 30 minutes. Please wait 30 minutes and then rescan the target machine.
If you continue to experience the same error or a different WMI error, please see the WMI Diagnostics article for additional troubleshooting and recommended fixes.