My HP nc6000 sound has stopped working

Hello,
Hope I'm in the right place but I have just discovered a problem and not really sure what catagory it falls under.

I have a HPnc6000 and this morning the sound just suddenly stopped from the Laptop speakers and the headphones.

I keep seeing reinstall drivers on other websites. Do I have to do this, can that just stop like that and should I have to pay for that??

I have Windows XP and IE version 7 if that helps?

Thanks for your advice in advance.