Actually if you failed t the first try when you install oracle on NT or windows, it isn't necessary to format your disk. Try to remove all the stuff using oracle installer, delete related directory and the items at start menu, then run 'regedit'. Search relevent parameters using keywork 'ora' and delete them, you can try your second installation. Trust me, I did that several times.
jabber, I am your friend's friend. Hope we can be friends.