Check the Sound setting in the Control Panel. Verify that the NuPrime DAC is selected. If it is not showing, the device driver was not installed correctly.
2. Go to Device Manager to check the USB audio device driver is installed and without any conflict. Remove conflicting USB audio devices. There are several places to check:
a) The NuPrime USB audio device listed under Device Manager.
b) In Device Manger, in "Sound, video and game controllers", there should be a NuPrime USB audio device. Check that there is no "error status". Right click to "Update Driver Software" if the status is "error".
3. Reboot computer.
4. Check that your USB cable is not defective.