Intel 670 3.8 in ASUS PTGV-LA

Newby here..

I'm trying to upgrade my HP Pavillion a1100y computer. Below are the specifics. I get an error when I install the CPU. The message is something to the effect of unsupported CPU. I'm going to give it another try, but wanted to know if I need to do a reset to the BIOS or something so that it will recongnize the new CPU. It currently has a Celeron 2.8mhz with 533mhz bus.

I have an Intel Pentium 670 3.8 CPU with 800mhz bus.

This is the motherboard in the HP.
Feature Specification
Motherboard manufacturer's name: ASUS PTGV-LA
HP/Compaq name: Grafito-GL8E

CPU/Processor Socket: 775
Supports the following processors
Pentium 4 600 series
Pentium 4 with HT
Celeron D

Front-side bus (FSB) 800 MHz (Pentiums)
533 MHz (Celeron D)

Chipset Northbridge: i915GV
Southbridge: ICH6

BIOS features 4Mb FWH EEPROM
HP BIOS with Enhanced ACPI, DMI, Green, and PnP Features Plus

Thanks
Dan

I forgot to mention that I did upgrade to the latest bios.
How can I see if there is another bios that will work with that motherboard. Is there a chance it's used in other PCs besides the HP?

If all else fails, is there another $50 motherboard that will work with this CPU and still work with a more modern CPU down the road when I need more processing power?