Motherboard is an Asus P5RC-LA, which HP/Compaq call Agena-GL8E.
Support CPU's :
Pentium D 820 (Smithfield, 90nm)
Pentium 4 631, 641, 651, 661 (Cedar Mill, 65nm)
Pentium 4 630, 640, 650 (Prescott, 90nm)
Pentium 4 520J/521, 530J/531, 540J/541, 550J/551 (Prescott, 90nm)
Celeron D 352, 356 (Cedar Mill, 65nm)
Celeron D 325J/326, 330J/331, 335J/336, 340J/341, 345J/346, 351, 355 (Prescott, 90nm)
Latest bios is v3.08 - 21/03/2006
ftp://ftp.hp.com/pub/softlib/software7/COL15010/pv-39894-1/sp26762.exe
So, I would guess not.