On a high end sound card there are DEVICE,WINDOW SOUND,CD,WAV and MP3 individual settings.
Right Click on the speaker icon (next to clock) and open mixer to max out individual levels.
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Application like Youtube and Skype has there own settings.
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Did you connect the CD to sound card cable?
Double check to make sure this cable is connected.
More sample pictures link
HERE
If your motherboard has built-in sound card then connect the cd to the motherboard CD_IN connector.