I've installed the os using an original Windows XP Pro SP3 OEM CD. I could activate it online using the key that came with the computer, but as this is a test machine for various "experiments", it ends up formatted very often, and i don't want to use the online activation so often, as I'm afraid MS will ban the key, and I'll end up with piece of paper full of olograms worth nothing.
I can assure you that the HP (CD4E1902) oembios files are not deprecated does it show the "HP & Compaq" strings when you run oembios.exe if so it is something that you are doing wrong in fact it should even be working with the ELITEGROUP (OEMBIOS.CAT CRC32=8EE1223C)