If you need to record from your sound card, you should try freeware Freecorder Toolbar. It works with ANY sound card, even those that don't support recording (like RealTek and SigmaTel).

If you want to record video with audio, you can use Replay Video Capture or WM Capture. Both programs use Applian Audio Driver, so you can record sound on your PC even if your sound card doesn't have the "Stereo Mix" / "Record What you hear" / "Waveout mix" option.