No stereo mix in windows 7

Im trying to get sound to work in bioshock, and I have to activate the stereo mix. Problem is, there is no stereo mix showing up in windows 7. any ideas?

Windows 7 is just a week of development mod made my like 2 guys and a homeless guy at Microsoft. Seeing as thats the case the two developers decided to make a windows vista mod and a homeless man burst through the window and beat the keyboard at least 60 times til his booze bottle busted and thus thats where the glitches come in and thats where stereo mix and add or remove startup programs were lost.

Therefore you might want to use vanilla windows vista and remove the mod called "Windows 7".