Very, very few things. Mostly, at this point, using TurboActivate on long unsupported versions of Windows (e.g. Windows 2000, Windows 98, etc.). Or if the user has the WMI service disabled and TurboActivate can't re-enable it: (from TurboActivate.h)
The hardware id couldn't be generated due to an error in the COM setup. Re-enable Windows Management Instrumentation (WMI) in your group policy editor or reset the local group policy to the default values. Contact your system admin for more information.
This error is Windows only.
This error can also be caused by the user (or another program) disabling the "Windows Management Instrumentation" service. Make sure the "Startup type" is set to Automatic and then start the service.
To further debug WMI problems open the "Computer Management" (compmgmt.msc), expand the "Services and Applications", right click "WMI Control" click "Properties" and view the status of the WMI.