Help making sound recording, no sound mix option

So i'm trying to work on a video project in Camtasia Studio 6. However the option to record from your speakers (what you hear) is not an option. After searching the net I found one common respond is to go to Control Panel > Sound and then the Recording tab and then make sure that all disabled and hidden objects are shown. However I still can't get Sound Mix or What you hear to show up, which is quite frustrating as I am sure that is why I can't select the Speaker audio option when i'm working in Camtasia Studio, that option is grayed out.
which leads me to question, is this a possible driver issue? I was thinking about installing the Realtek Audio Driver but not sure if that would do anything different or not.
Otherwise i'm lost as every place I have looked online just suggests this as an option (checking to make sure all disabled and disconnected devices are shown in Sound)
So not sure really what to do? anyone have any suggestions or advice?
I've posted some pics that might help explain a bit better.

Im having the same exact problem and when i tried to install the realtek drivers vista wouldnt let me ! .

Ive tried to record using Audacity , Camstacia and adobe but need to enable this option but how?

Ok i worked things out i used to have the latest driver from EVGA webpage for my sound drivers on my motherboard , but it seems this drivers where not the latest because the soundcard added in the EVGA motherboard is from realtek i think , so i downloaded the latest driver on this forums:

http://www.vistax64.com/sound-audio/64250-latest-realtek-hd-audio-driver-version.html

installed them and on control panel at last the recording device "Stereo Mix" appeared :D! , thank you so much vista forums (and yes i have been recording audio coming from my pc now )

i think a windows vista update disabled the stereo mix before but adding this new drivers enable it again *phew*