For those of you wondering how to record the sounds outputted by your computer, this simple post should configure Windows to allow you to record the sounds with programs such as Fraps.
Load up Fraps and hit the Movies tab. Make sure Record Sound is checked and Detect best sound input is selected. Next, head into Control Panel, Sounds and Audio Devices (in classic view).
Click the Audio tab, and under the Sound Recording section hit Volume…
Click Options, Properties at the top and you should see a window similar to the above. Check the box that says Stereo Mix and hit OK.
A new section should pop up in the main window called Stereo Mix. Unmute it if necessary, and you should be good to go to record sounds from your system.