Check the sound setting on the computer by following the instructions below.

(1) Connect the DDJ-1000 to the computer.

Open [Control Panel] - [Hardware and Sound] and click [Sound].

(2) Check the sound setting.

If the DDJ-1000 is selected as default device, click a sound device other than the DDJ-1000.

Click [Set as Default].

(3) Close the Control Panel. See if you can change the volume of the computer speaker.