Hi,
thanks for your replies !
As I had problems to even access the specified "config" directory, I have now solved the problem, by resetting my computer to the factory state. I then had to run windows update for a period of some three years, and so I could learn a lot about it.
I think I now understand the nature of the problem: The hive "Components" is not always present! It seems to be built up by WindowsUpdate while collecting applicable fixes. When your WindowUpdate is then actually executed, the information contained in registry hive "COMPONENTS" is then mapped against the contents of the folder: C:\Windows\System32\config\COMPONENTS
Once WindowsUpdate has completed, the hive COMPONENTS in the registry seems to be removed again. This is why sometimes you can see COMPONENTS and sometimes not ! However these two COMPONENTS data sources in the registry and on C-disk can get desyncronised.
In my case, a certain entry in the Registry was expected, but could not be located and so WindowUpdate crashed with Error Code 80073712. Obviously it is not so easy to get this problem fixed ... ! If wrong entries are entered into the registry, you may change things from bad to worse!