1) Be sure that the card you're installing is the correct AGP voltage!!!
The voltage specs for AGP were changed somewhere when the P3 was popular (I believe when they went from AGP 2x to AGP 4x).
If the card isn't recent enough to support AGP 4x, the card AND possibly your motherboard too could be seriously damaged!!! So check this before continuing!

2) Before doing ANYTHING else when installing your disks, install Intel's Application Accelerator first !!!
This little utility will enable you to use your disks past the 137gig barrier that windows 2000 has. Without it, you would also be able to partition and format your disk, but at the first reboot all sorts of weird error messages would appear.
It will also enable RAID0 & 1 for your chipset on windows 2000!
Thirdly, it will enhance the overall performance of your system.

I hope this helps.