Hi,
Please try this first to enable Speakers in Playback devices as follows:
1. Right click speaker icon (right hand corner)
2. Select Playback devices
3. Right click Speakers
4. Enable it and set as Default
5. Click Apply/Ok
otherwise please use the following instructions to check and fix:
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01912228&cc=ad&dlc=en&lc=en&jumpid=reg_r1002_usen
Regards.
