You need to go to Edit/Audio Hardware Setup and make sure that you have your correct audio device selected for input and output. I have installed Audition on a new desktop. The message appears: "The audio input is not activated. Recording audio is not possible. Check your audio input.
Configure audio inputs and outputs ยท Choose Edit > Preferences > Audio Hardware (Windows) or Audition > Preferences > Audio Hardware (Mac OS). Have selected your Audio Input/Output card in the Audio Setup. If you're trying to use onboard audio and it's a recent lap top with Win Vista.