You don't need to get windows 2000 booted up to change bios settings. Most of the time you can enter the bios by pressing <DEL> or <F1> on the first screen during boot (POST).

Booting from a win98 bootdisk won't work. You need to boot from the CD specifically. This can be set like so in the bios. However, some CD-roms won't let you boot Cd's from them, no matter what you try. In that case, you need a windows 2000 bootdisk. If you don't have one, you can download one from http://www.bootdisk.com/

Good luck!