Cpuz is having a problem reading your board. Do you have the latest version of cpuz? In any case, I would try another version or a different monitoring software. Your voltage should be 1.0-1.1 volts. If you don't have any symptoms or problems with your system, I would not worry about it. Not all software is accurate for all motherboards. Don't open the case or fiddle with your board; this may void the warranty.
I would remove your current cpuz version and try another older one, or everest. And stop worrying about the voltage. It's not adjustable with an hp board; you're covered under warranty as long as you don't fiddle with it.