Welcome to CDFreaks/MyCE Club…if you are lucky, someone will post you a funny hat with big round ears 
OK…More info may be helpful…
- what is your OS?
- how old is the HP?
- when/how did it stop?
- have you changed anything recently?
However…I checked MS, and found a possible solution: Please try the following, and report back to us;
To work around this problem, exit Windows Media Player before you insert the disc. Or, if the audio device is not enabled, use the Sound item in Control Panel to enable the audio device. To enable the audio device, follow these steps:
- Click Start, click Control Panel, and then double-click Sound.
- On the Playback tab, right-click in the blank area under Select a playback device below to modify its settings, and then select Show Disabled Devices.
- Right-click an audio device, and then click Enable.