Hi
I have this game that im trying to get to work and the only system requirement i still need is a Pentium 3 processor 800MHz.
I have a Pentium 3 500MHz and i was wondering how to upgrade it from 500 to 800

Something

You would need to hunt down a slot 1 Coppermine PIII 800 with a 100MHz bus, then you'll need to make sure your BIOS supports a Coppermine (doubt it does) since you currently have a Katmai PIII 500 in that thing right now.

If it doesn't then you'll need to update your BIOS to the latest or to one that does support a Coppermine before you even consider buying the PIII 800.

Or you can just get a newer PC - it's about time don't you think?

Well your probably right about the need for a new PC but for the moment il stick to you other advice. Is the Coppermine PIII downloadable software or is it hardware i have to buy?

Something

Actually don't bother replying ive found out its hardware.

Something

All of the slot 1 boards that I've seen capable of running Katmai P3s have been able to take Coppermine P3s without requiring further BIOS updates. The BIOS updates were usually needed only to update Pentium II boards to support SSE instructions, which your board already supports (since it's already running a P3).

As long as the P3 is of Slot 1 form factor, and runs at a 100MHz bus speed (as Sabertooth's already said), it will work.

Pentium III--Descendant of Intel Core.
Pentium III-S 1400 @ 1.63GHz, 512K L2
X800XT AIW OC 580/600
2GB of RAM
250GB HD
SB Audigy 2
QDI Advance 12 mobo
Smugly running Vista