When you connect the keyboard to the computer using audio cables, before you record, do you hear the keyboard through your computer?


Also, make sure that your computer is set to record using your sound card’s line in.

You can check this by going to start, programs, accessories, entertainment, volume control.
When in volume control, go to properties. Select your sound card and go to “adjust volume for recording”. Make sure that the box for line in is checked.


HTH