my vista xp dual boot gone bad

I decided to load xp onto my vista machine following the tutorial from this site. all went well until i am supossed to put in my vista disk... i dont have one, (i know, i know, i have learned)

i downloaded a copy of vista but when the machine boots up with the vista disk in, it starts loading files, then the windows logo with timebar comes up for a little but, then my cd stops spinning, and the screen goes black until i turn of my laptop

any help would be greatly appretiated

it boots into xp fine but i can not get into vista