another bios ? DB again

OK everyone says Dual boot has nothing 2 do with bios, but my bios asks which HD to boot from so I don't see why there should be a problem w/this. I've got a OEM XP version coming from a reputable company, can't I install it on disc one and boot w98 from disc 2 when I want 98? I boot 98 from Slave (HD2) now. or will an OEM xp get wacked when I run it (without disabling HD2)??? I dont understand why this doesn't work