Inside Windows-Update

The tecControl utility can be used to experiment with GetSystemSpec(). Just tick the tags to be passed to it, select an output file for the XML result returned by the function, and open the saved XML file with Internet Explorer to view it. The tecControl utility does not support updates of iuctl.dll or iuengine.dll, because it passes a NULL interface parameter to Initialize(). If an update is required, the utility will display an error message. In this case run Windows Update once to perform the update and run the tecControl utility again.

As can easily be seen the <regKeys /> tag causes a list of registry subkeys of HKEY_LOCAL_MACHINE\\SOFTWARE, i.e. a list of the vendors of all software packages installed on the user's computer, to be included in the result.

The tecControl utility is complemented by the tecDecode tool, which extracts the PID attribute from a saved XML file, decrypts it and displays the product ID and the timestamp. If a product key is specified, then its SHA-1 hash is compared to the SHA-1 hash stored in the PID attribute and the tool indicates a match or a mismatch.