If you can see adjustments for FSB/Clock Speed Ram Speed and timings etc, then it's possible, but I highly doubt those options will be there, so more than likely no, you cannot overclock it.
The only possible ways would be to see if there is an updated BIOS on HP's site, that *could* make the system run snappier, or flashing to a compatible BIOS for your make and model of motherboard, depending who makes it etc, but there is a very high risk of completely borking it.