Such software basically tries to tell the BIOS to use a faster FSB. That generally means you won't be able to raise the vcore for stability and will thus be limited by the stock voltage. Not too many people here overclock using software on a locked BIOS .
Overclocking on your current setup will serve no purpose other than to raise your electric bill, heat your living quarters and potentially burn up your computer. A Northwood P4 is so far behind the times that even if you made it to 5 GHz (you won't!), it wouldn't be worth a crap for most tasks. Even a humble Core 2 Duo (we're talking about a $80 CPU) would absolutely destroy your CPU in any given task.
So what do you intend to accomplish by overclocking? I guess that's the question we should all be asking.