dual booting

[musicfret]

Hey everybody, sorry I haven't been involved since my introduction, been working on a few computers at one time. My question is how do I go about setting up my dual boot computer? I'll explain what I've done so far. I have installed my windows xp home on two different hard drives. I set each one to primary setting and installed the os on each hard drive seperately. They both work great seperately. So now, I ask, if I set one of the hard drives to slave and attatch the ide cable to both at the same time, which will the computer use to boot????? Assuming the computer boots at all!