I did not pick this up until recently but the 'Sound, video and game
controllers' category is missing from my Device Manager.

Instead everything that would normally be there is listed under 'Unknown'.

This is not a case of them being an unknown device as all the latest drivers
are installed and the devices themselves are working perfectly fine. I can
for example play sounds/video and games without any problem at all.

What I have noticed is that if I goto the properties for example of 'Video
Codecs', although it tells me that the device is installed and working
properly (and indeed it is), it does not however give me the option of
viewing the installed video codecs.

I am puzzled as to why they have been lumped into this 'Unknown' category,
and removing/reinstalling each of them made no difference.

I have a screenshot of the Device Manager he
http://www.dsm.id.au/hmanager.jpg