You probably don't want to do that, anyways.
How much space are we talking here? I know that Dell uses a very small (under 50MB) partition for diagnostics and utilities, but I don't know how big HP's partition is.
Knowing how HP likes to work, I wouldn't delete the partition. More than likely, that's an image of your system's factory-fresh installation on it; delete that, and you might not be able to restore your system when Windows XP tanks out on you.