Hi,
Even new systems come with old drivers. If this does not solve issue or you experience other problems
get HP support involved as the more you change things the more they will claim it is something you did.
Control Panel - Device Manager - SOUNDS - look for HD Audio - Mine says RealTek High Definition Audio
Write down description make and model - double click on it - drivers tab - write down version. Now
Click UPdate Drivers which may not do anything as MS is far behind certifying drivers. Then RIGHT
CLICK on it and UNINSTALL - REBOOT - this will rebuild the driver stack.
1st go to system maker's site and look for latest driver Download - SAVE - go to right click on and RUN AS ADMIN
(This is your fallback.) REBOOT after each driver installation.
NOTE : Sound driver often rollback so check the version after installation and the reboot to see if the version you
installed is there, if not repeat - reboot until it is. It can take several tries depending on how many rollbacks it
does.
HP Drivers - you will need complete model info.
http://welcome.hp.com/country/us/en/support.html
Then do same for Device Maker's site.

Manually look at manufacturer's sites for drivers - and Device Maker's sites.
http://pcsupport.about.com/od/driverssupport/ht/driverdlmfgr.htm

How to Install a Device Driver in Vista Device Manager
http://www.vistax64.com/tutorials/193584-device-manager-install-driver.html
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Error “the Audio Service Is Not Running” When Opening the Volume Mixer in Vista
http://www.winhelponline.com/blog/error-the-audio-service-is-not-running-when-opening-the-volume-mixer-in-vista/
Also Right Click Speaker near clock - Playback Devices - right click in the box area - check
Show disable and disconnected devices. Highlight speaker and the on lower Right click Properties
check settings for Device Usage enabled and so on. Also do same for Configure on Lower Left of
that box.
In Control Panel you can also look for an Audio Manager along with the Sound Settings.
Problems with sound and audio or no sound - a Mr Fixit
http://support.microsoft.com/gp/no_sound
Tips for fixing common sound problems
http://windowshelp.microsoft.com/Windows/en-US/Help/1e87a3e8-c0e8-49af-980f-9eb6686f42d21033.mspx
Speakers and other audio output devices
http://windowshelp.microsoft.com/Windows/en-US/Help/a43f3a31-6d9f-49d1-be22-e2f47b8b1f2c1033.mspx
How to Enable Hidden Audio Devices in Vista
http://www.vistax64.com/tutorials/143447-audio-device-enable-hidden-devices.html
How to troubleshoot sound problems that you experience after you install a Windows Vista Service Pack
http://support.microsoft.com/kb/948481
Hope this helps.
Rob - Bicycle - Mark Twain said it right.