Open Cakewalk Sonar.
Click "Options" on the top menu bar, scroll down and click "Audio." The "Audio Options" window will appear.
Click the "Advanced" tab.
Click in the drop-down menu next to "Driver Mode" and select the option that applies to the drivers included with your soundcard. ASIO is the most efficient option.
Click the "Drivers" tab.
Click in the box next to the drivers you wish to use for audio input and output. For example, if you were using an M-Audio Fast Track Pro interface, you would click in the box next to "M-Audio Fast Track Pro" under "Input Drivers" to put a check in it and use it as an audio input.
Click the "OK" button.
Click the "OK" button in the pop-up window that prompts you to restart Sonar.
Click on the "X" in the corner of the screen to quit Sonar.
Reopen Sonar to use it with the correct audio drivers.