booting from an ATA100 HD

I have a computer that we recently built, It has an asus A7V, mb with a duron 800 cpu. I have put a western digital ata 100 20 gig hd on the ata ide controler (promise),I have installed win98 an made sure the drivers where installed for the promise ata 100 controler, I can not boot from this disk unless the win98 cd rom is in the cd drive. It boot fine when i put the hd on the reg ide controler. Anyone ran into the problem an found a solution for it.

jack
jmalone@horizonind.com