WM Recorder and Replay Video Capture are the only Windows applications I know that can record video with sound even if you don't have Stereo Mix / Wave-Out Mix / What You Hear. Both screen recorders are compatible with Windows 7, Windows Vista and Windows XP.

Make sure to use the Universal audio driver when recording with WM Recorder or Replay Video Capture. And make sure to a screen recorder before starting an application you need to record from.