this is the 3 ways i think you should follows… check the cmos set-up and change the first boot setup to hard disk…. Or check if the cable you connect to the hard disk was from the IDE 1 socket..ok.
OR put a window 200o server to repair the hard disk.
Even if you can get the BIOS to recognize the drives odds are the Windows 2000 won’t boot. The hardware (motherboard, chipset, etc) will be so different that Windows won’t have any of the drivers installed for the new hardware. A repair might fix the problem, but you may have to reinstall completely.